Nothing that can be done about ugly. Fat, well, sometimes we can slim down a little. Unwashed shitcakes? As a masseuse, you can always insist that all customers take a shower before the session. Just like they do at public swimming pools.
Make it something fun, like, "I'll help dry you off, after, sexy, now go wash that body of yours for Mama".
Really, I do not understand how anyone would want to lie down with someone else, even hired help, without first hosing themselves down. Yes, I expect the same from my SP. Last thing I want to see is another guy's cumstains on a pair of boobies.