This is a bit more labor intensive, but you could hand wash the spin shorts.

Just a small amount of Woolite in the bathroom/kitchen sink does the trick.

Turn the shorts wrong side out, and give the chamois a scrub. Rinse out well, throw in the washing machine alone on just a spin out cycle, and viola... hang up to dry overnight for the next day's class.

I just leave mine turned wrong side out to dry. I think it helps the thicker part of the shorts, the chamois, to get dry quicker.

FWIW
Miranda