You don't eradicate mites on a snake with a bath just like you do not eradicate fleas on a dog with a bath either.

Adult mites are not the only problems and even if you believe that you eradicated them all, eggs will still be there.

Personally I prefer to eradicate them as quickly as possible knowing that they are gone for good. drowning in water, or water and dish soap and other methods are nothing new and just a waste of time.