The best way is to get rid of the old wool.
Alternatively, you could try hanging it on the washing line for a couple of days
This would also be my suggestion. Several sunny breezy days on the line should do the trick.
Our natural inclination for fresh air and sunshine deters them. An occasional roll in the hay helps, too.
It is not the moths that savage the wool; it is the larvae. They require undisturbed, dark places.
Wool has a very pleasant smell if it is well-kept. The oils in your fabric may have gotten rancid. That, along with mothballs and years of being closeted without good ventilation, produces a dreadful odor.
Just wash your fabric in shampoo, as was suggested previously. It may require several changes of shampoo-water solution. Squeeze gently, but do not agitate, or you will end up with felt. Dry flat, in the air, squaring the fabric along its threads.
During the last rinse, add liquid lanolin, which you can get at most natural foods stores. Or, if you truly do object to that odor – and I’m at a complete loss to understand how that could be – use heavy mineral oil instead.
A bit of shrinkage might improve the fabric for your intended use, as it will render it more able to hold heat.
Are you certain this is wool? Shred off a bit at one edge and light it with a match. If it smells like burning hair and produces a fine ash, it is wool. If it smells like burning plastic and produces little hard balls of residue, it is synthetic.
Be sure this is not something like a Harris Tweed. Is the fabric only about one yard wide? Is “turf fire” part of what you are smelling?? Does it have a label saying “hand woven?” Does it LOOK hand-woven? If so, you’ve got something quite valuable.
OK… 7 pounds!
Ok. I’ve only been hunting a couple of times and that was for rabbits and quail, which I guess is different from elk hunting. It seems to me (a novice, I admit) that the wet wool aroma could be an asset in your hunting. You just need to change your game from Elk to other big game like say grizzly, wolf or mountain lion – the ones that are more inclined to fight back, and they would also be the ones with a taste for lamb or sheep. In this way you’re sort of the bait cause when they come sniffing around for those tasty lamb chops, they find you instead. Then its mono-on-mono, and as they say, to the victor go the spoils. Makes me think of Hemmingway’s code.
How do you get rid of the wet wool smell? I’m not sure. The smell does remind me alot of wet dog, though. Sorry I can’t be of any real help.
In reading my post it sounds like I could be someone who has a problem with hunting - just wanted to let you know that I don’t. I was just sort of wondering how well my idea of attracting certain big game would work - not that I really care to be the one to try it out of course. 
Will,
Thanks, that is very helpful. 
Bear hunting, as it’s done around here, never interested me. Sitting for several days over a decomposing horse or barrel of rotten donuts…not my idea of a quality wilderness experience.
Lamby, this isn’t harris tweed, and it doesn’t look hand woven, but it definitely is wool–I’d know the feeling anywhere. And for the record, I rather like the wool smell (though this does have a twang of mothball to it, which I could do without). It’s the elk that don’t seem to care for it, based on experience.
Thanks for the suggestions, everyone. As it’s turning out I’m not going to have time to finish up hemming the thing before my trip anyway…
Tom