Animal Grooming?

We normally think in terms of grooming animals but the report (http://news.bbc.co.uk/1/hi/world/americas/7532248.stm) that freshwater fish (Garra rufa) are being used in a Washington Beauty salon to deliver pedicures to people is an interesting development. The minnows in question normally graze on algae on stone surfaces but, in hot ponds, have been known to nibble the dead skin of bathers. They apparently polish the toes of people who dangle their pinkies in the specially prepared (clean water for every client) tanks. Do they have to be hungry to do a good job? If seawater was the preferred medium, one might get Cleaner wrasse to do a similar exercise (they normally remove parasites and dead scales from other fish who present themselves for grooming on the reef)? There are also cleaner shrimp (see above) who might well do a similar job with fewer animal welfare concerns (they are invertebrates). Where will it end? Monkeys would happily remove head lice and their nits from people's heads. Perhaps small sharks could be encouraged to use their 'sandpaper' skins to buff people's nails? They would, of course, have to be trained not to bite.