I may get kicked out of the "Angler's Croissant for Lunch Bunch", for saying this, but............. why would anyone "wash their waders", to begin with? Short of a "reallllly bad accident" in waders, I don't think I've ever seen a pair, let alone any of my own 4 pair, that "needed" washing!?!
I have 3 pairs of "breathable" waders, (Gillies, Chota and a pair of "no-name, but the price is too good to pass up", chesties)) and none, after 5 years for the Gillies, or 3 years for the Chotas, 3 years for the cheapies.... have shown the slightest need for "revamping" to keep them breathable, and/or, water repellent.(that's fishing about 125 days a year).
Each trip, when I return home, I turn whatever pair I've worn inside out and hose down with fresh water, while hanging upside down and allow to dry.
Now, granted........ there has been a few camp stew "incidents" over the years, where I've been virtually scared to death, to loosen my chest belt at the end of a hot day's fishing....... but nothing serious enough to require a washing machine, later!?!
For my regular Gortex clothing, I ran across a product called "Nikwax" about a year ago, at one of the local surf shops in my area. The surfers use it on all their Gortex gear, from waterproof gear bags, to jackets and pants. It's made in a sort of "shoe polish liquid" for shoes, to keep leathers breathable and a wash in solution, for Gortex, breathable, outer wear.
Nikwax is NOT a detergent and they make several products to treat various types of gear, from down sleeping bags to straight cotton clothing, to even tents. Their website has the list, tips and tricks on all their products of course. (Just a .com after the name.)