I think the fish could be quite nice - I'd give it a try if I happened to be at a spa where they did it.
I don't think I'd go out of my way to find somewhere to have it done, and I wouldn't pay out a lot of money for it.
So basically, it's not likely to happen! 
I once had a pedicure at a spa (I only go to spas about once every five years), and the girl used a kind of electric sander, and wore a thing like a welder's mask - and my feet are not that bad!