There is a thread on DYI washers in this forum. Search for Archival Print Washer Kit. In the thread, Jeremy Moore posted this link to a vendor: http://fineartphotosupply.com/printwasherpage.htm. It provides the "insides", you provide a 10g aquarium tank.
You could build a print washer. You could also eliminate the need for one. By using an alkaline fixer, you eliminate the need for long wash times (and the need for hypo clear). I've been using Formulary TF-4 fixer for a couple of years now. They recommend a wash time of 15-25 minutes for fiber paper. I tend to give prints a long soak and then a short wash. I've seen no downside whatsoever.
At the moment, I have a book from my local library called "The Photographer's Build-It-Yourself Book" by Tom Branch, published in 1982 by Amreican Photographic Book Publishing. It gives detailed instructions on building an archival print washer. Maybe you can find this book at a library.
I built a couple of my own, depending on the size of the paper (no use using a 24 x 12 washer to wash 8 x 10) I got some off-cuts of material cut cheaply, and glued them up. Ten years on, they're still working perfectly. Instead of paying £300 each, they cost about £30....If anyone wants more detailed info, mail me at firstname.lastname@example.org with your address and I'll send you instructions.