What do you keep your temp and humidity set to in the enclosure?

Your other snakes will be fine, just wash your hands with anti-bacterial soap before handling your others if you touch the sick animal.

When dealing with RI, keep your hot spot around 93-95, and then keep your humidity in a lower range like you said you were originally doing.

I've never tried the method in the link below, but it seems like it could be worth a shot, since Vet treatment would put a hurt on your budget.
http://ball-pythons.net/forums/showt...-from-Home-DIY