lice treatment sounds to me as if it could be a shampoo to wash furry animals like cats or dogs with, or something to put into the fur. snakes dont have lice, lice live in fur. doesnt seem fitting.
for bathing your snakes, you really just need to add one little drop of dishwasher fluid to the water, that breaks down the surface tension and ensures the mites will drown. i see no need to apply anything else to the snakes.
provent a mite is the quick and easy way to kill all mites in or around the enclosure, but good old hands-on cleaning with hot water and diluted bleach will also do the job.