I can honestly say I've tried this long long ago. I started as an i'll informed crayfish owner, and watched the fins on most of my fish get shredded. I clipped one claw first knowing that they grow back, but my fish were still under attack. I'm talking Oscars and large gourami's not little fish. next I clipped the second claw, and then the poor crayfish became lunch within a few minutes after his defenses were removed. The next crayfish I own will be in a crayfish only tank. The only decent cleaner (non fish) I've found with a medium sized cichlid is the larger snails. there is still some risk, but I do have 3 mystery snails in with my Oscar and demsey, and the fish don't seem to even notice them. I feed ramshorn snails to those fish regularly, so I know it's not due to a lack of appetite for escargo.my slp told me that crayfish can be used as bottom feeders . supposedly you cut ff their claws and they grow back after4 months. i currently have a 4.5 inch blood parrot . woud this be ok as it kills other fish