Ball Python RI home cure needed,

[mykee]

If it's leaking saliva, you have a very advanced RI. With those symptoms, this animal could easily drown within a weeks time without veterinary attention.
Also, your "home care" is not only doing no good, but could be causing harm. The menthol is the worst of the lot. Stop immediately. Soak down his enclosure to get the humidity up to 90+% and bump the temps to 100 degrees until you can get to a vet.
Also, snakes don't cough. Its physiologically impossible.