It depends. As a whitewater paddler I face similar problem with dry tops, life jackets, etc.
Might check your wader instruction manual as some are machine washable (HE machine - no agitator) but you will want to buy tek-wash ( http://www.nrsweb.com/shop/product.a...3&pdeptid=1035
)or similar soap from an outfitter as regular detergent will mess with the DWR. I also run the machine empty to get rid of risidual soap in machine before I wash.
If it's not machine washable I have found white vineagar soak in laundry sink or tub for a few hours will kill the smell for cheap. There is a slight vinegar smell the first couple times you use it. So if that bothers you buy some sink the stink or similar
Hope that helps!
You know it's bad when you go "What's that aweful smell" only to realize it YOU