^^^^ +1 ^^^^^
Many fish will go after these but the ones mentioned above will do the job for you in no time.
Flatworm exit can do the job too but comes with a risk.
Sadly yes they are. A couple things as posted above get the wrasse or treat the tank. Please note if you treat the tank FOLLOW the directions and use carbon to rid the tank of toxic as soon as the treatment is done. Best of luck