As far as a clean up crew, from what Ive read. It depends on whether you get a smasher or a spearer. Peacocks are smashers and if you get one thats anything like mine, it will smash through snails whether she is hungry or not.......however, she does leave my scooter blenny alone, for now. Spearers, I think, are more prone to leave your CUC alone, but you wont be able to keep any other fish.....HTH! : )