I have a few that do the same. I also have one of the messiest ball pythons ever. She finds it funny to stroll through excretions on a regular basis which is just a horrible mess to clean.

I would suggest bathing your BP much less than you do now. I know you haven't seen anything yet but you could dry out the skin bathing that much. Honestly the only time I ever bathe a BP is if they are being treated for mites or they made a mess of themselves.