Sir, you are preaching to the choir.
What about the lady herself? Aside from what should be perfectly obvious (showering, deodorant, perfume, fresh breath)I have a nail brush that I sanitize with alcohol after every use and use it to scrub under my nails after each session.
This is also why I get testy if anyone were to complain about rates.
If you find a provider who a. Provides the service she advertises she does, b. Has a clean, nice, safe and discreet in-call (whether that be private or 'tel, point being that she keeps her space CLEAN) and c.Is professional, you really can't ask for more gold than that, in this biz.