Does anyone have any recommendations about what sorts of materials seem to work well for them, when making chanter rushes? It would be nice to find something that doesn’t tend to fall out the chanter. I’ve tried nylon cord, but it seems to like to slip out every once in a while. And YES I HAVE tried bending it… all sorts of funny ways as a matter of fact! 
Hearing everyone’s firsthand experiences with whatever they’ve tried would be great! Thanks in advance! 
Orbis, is there some specific reason you are using string? Have you tried thin wire, like florist’s wire? This would allow you the ability to make a loop/circle that would hold one end steady in the bore.
djm
LOL… String?? sorry… I guess the term “cord” could be misleading… lol… nylon string probably wouldn’t work too well would it?? That just left a funny visual impression in my mind… I can just see someone trying to stuff a length of nylon string into the end of a chanter, and then attempt to make it stay there! At any rate… what I was talking about is really more like the nylon you might use for a weed-eater… thick stuff… sorry if I was a bit vague with my description… But thanks for the reply, and the laugh!
Its about time we got some sense of humour back on this board. 
Regarding the weed-eater cord, you can also afix this inside the chanter with a bit of paper-clip wound up inside to hold it steady, but that’s an awfully thick rush. I have seen various thicknesses of wire, or even a stick of spaghetti, but nothing as heavy as weed-eater cord. Do you need this for very much of the length of the bore, or just at the bottom?
djm
Something that has worked well for me is an inch and 1/2 length ( or whatever length works best for you) strip of .015" styrene, rolled and fit into the bottom of the chanter, it will ‘unroll’ itself to fit the bore diameter The width of the strip should be on the ‘thinish’ side, around an 8th of an inch. It will ‘unroll’ itself (or you can give it some help) and I have found that it will stay where it is put.
Hope this helps.
This is precisely what D. Daye tells you to put in his chanter when you get it and it doesn’t play in tune - in fact TWO lengths of it. It is truly thick stuff. And WOW what an autocran you get then too.
Guitar string.
yes guitar strings work well phosper bronze 42 gauge (Martin I think) is in mine at the moment.
Along with a Yoghurt pot strip u in the bell!
Oh and some black tape over the back D !!
And I have to sit in a bath of Custard to be spot on in Concert pitch
(Great at sessions) 
I’ve been using thin brass wire purchased in a hobby store. I put blue stickey take or plumbers tape in the approprate spot. The brass wire is just thick enough that, if bent slighly in the middle like this (, it stays put in the chanter . I use a rubber “O” ring to help the bottom d.
I use a lightweight guitar G string long enough to reach just above the A, tuning individual notes with a lump of poster putty, another lump in the bell holds it in place and tunes hard D at the same time.
I only need to rush my chanter in the winter. In the summer, usually a tad of poster putty in the top of back D, bottom of ghost D and sometimes a little dab in F# and the bell does the job for me.
Musical wire, sold in hobby shops. Just bare metal. File the ends down smooth so they don’t scratch the bore. Cut a short section and wrap string around it to thicken the rush in a certain place. Or cut a small strip of cane and wrap that on with string, if you want a thicker rush (i.e., bass regualtor). The tuning can be adjusted as fine as you want this way.
If you use guitar strings etc., consider using chrome wound or the like - Paddy Keenan wore grooves into the bores of his pipes through years and years of yanking guitar strings out.
That weedeater (stringtrimmer in UK) cord works great. You can get it in a very wide selection of guages and particularly useful in the lower bore where you need to correct G, F, A octaves etc, and where a thin wire makes little difference. In the upper bore, guitar strings or piano wire.
Any of these stiff wires/cords need only be bent in half or in a zigzag to wedge firmly into the bore, no special devices needed.
The bottom D you can bend one of those weedwhacker cords into an U and put it into the bore either way, depending on how much flattening you need–bend up farther into the bore is flatter, and also helps the ends grip the wall better, or bend down, just inside the entrance, to flatten less.
I guess if you’re not playing a Daye PC at 5400 feet with a reed you’ve mangled it isn’t a problem. I’ve got a 14-year-old son who I forced to strap into my PC setup for the first time playing anything, even a whistle, and He didn’t have any problem playing a solid bottom D and running up and down the scale in both octaves.
Must not be the trimmer cord.
Royce
As mentioned, wires, strings or nylon chords are best bet. According to my exprience, the material´s surface should be smooth and it should be fairly hard to not influence or get influenced by the vibrations. The further down the chanter, the less likely is this anyhow. I used steel wires of various diameters because they can easily be softened and hardened again (e. g. just above a candle), get springish and then stay in position. With a „shover“ (a stronger brass wire e. g. longer than the chanter) they can be shoved in or out again. Occasionally, I even rushed staples of reeds that sounded great and when a wire didn´t seem to take away the reed´s brilliance (For example, a sharp „area“ above 2nd octatave g was flattened by a thinnier wire about 4 cms long and the end bent over itself like a little walking-stick and shoved 3 – 4 cm up the staple).
Rushing is but merely a matter of trial and error cause like men (at least still) chanters and reeds all are a bit different. Yahama San wouldn´t like this and Henry Fard wouldn´t have liked it either.
The big advantage of rushing is but that it is temporary and can be removed again. A piper can adopt his/her chanter to climatic changes and take out the rush afterwards again. It also is very apt for vintage-chanters cause on a closer look the rushing easily can be seen (and sometimes removed with a different reed).
In addition to the tuning it can but also influence the chanter´s „performance“. A most striking quotation (Henry Hopkins) springs to my mind here: „The difference between a good chanter and expensive firewood is only as strong as sawdust“ (BTW, Blackwood and Ebony both have nice, nearly white ashes). It is my opinion that you can get a lovely sound, perfect tuning and good performance out of each and every chanter – with very few exeptions. This „reedmaking“ is but a matter of time (and therefore money). You might have a „quality“ chanter because their reeds are much less liable to climatic changes and the reedmaking is much quicker. Deceicive for the quality of a chanter in my opinion is not its sound (that changes with the reed) but the time it takes for the reedmaking (mostly the reedmaker is not the maker of the chanter). It becomes clear that the quality chanters are cheaper in the end though buying them might be more expensive at first glance. Much more „know how“ is built into them from the start.
Best
Hans