As long as the salt is added for each recursive iteration, it should destroy any kind of cryptographic hints given by hashing a hash. So you shouldn't be doing F(F(F(X))) rather it should be F(SALT + F(SALT + F(SALT+X)))

But anyhow, I was talking about increasing the security of an already-existing hash algorithm. Even if the recursive hashing isn't that much more secure, it definitely isn't less secure than one pass...