I put one of those plastic tie raps in my silkstone:

and heigh presto I can now hit that third octave E with ease
and without damage to my eardrums. So for Danny Boy in key of C just insert a tie wrap. Previously I had to resort to my Clarke Original for this tune. My untouched Silkstone will hit the E but it is very LOUD and very sensitive to breath pressure.
OK OK I know this silencer trick has been aired before. The first octave is much the same but the second is definitely quieter. However one fly in the ointment: if you have good ears (I do not) you will notice pitch changes too.
Another one aired before: which D whistle is best for third octave?
Brian