put the prints in a tray, a bigger tray than their measurements, ( 11x14 for 8x10, 8x10 for 5x7 et. c )
back to back and face to face.
fill the tray with water with a measuring cup
shuffle the prints in the tray 1 full cycle ...( so the top pair is on top again )
dump water in your recycling bucket
repeat 20 times.
you don't need a sink, you don't need a bathtub you don't even need running water.
wash your FB prints the same way .. back to back, face to face &c &c .....
you should do a residual silver test on a print to make sure how long you need to wash it may require more than 20 fill n'dumps
especially if you don't use fixer remover / perma wash &c ...
good luck !
john