I read somewhere not too long ago, I think it may have been an Ilford data sheet, that general drying time for 4x5 is only about 20 minutes. I've actually found that to not be too far off, it would depend on your climate through I guess. I develop my sheets individually, and by the time any subsequent sheets have finished in the rinse and ready to hang up, the previous one is nearly completely dry, with just a final drop waiting to fall.
Best hanging system I've found... a good old wire coat hanger with clothes pegs across the bottom, you can safely fit three, maybe four 4x5's across the length of it.
With regards to hanging them in the bathroom, a neat trick is to run the hot tap for a while first (or, in reality, hang them up after someone has had a shower). That way the steam collects any dust in the air and drags it down with the moisture as it cools. Instant clean-room.