Cleaner wrasses are probabley the hardest fish to keep in a closed sytem. The foods they require cannot be provided for properly and they often starve or slowly waste away. When "cleaning" a fish in the home aquarium they are not actually removing any protozoans. They are scavanging fish slime and scales off other fish in abscence of their natural foods which is not C. irritans
. Please read ... Labroides wrasses
The next best hope is either a sharknose/neon boby or as mentioned a cleaner shrimp. These too offer false hope. In the wild, animals of this nature have success due to the fact the fish is not in a closed system like our tanks where they can become re-infested. These "cleaning" animals may offer temporary relief for the fish but do absolutely nothing to rid the environment (your tank) of the pest parasite.
If you seriously wish to have a parasite free environment for your fish, setting up a >>quarantine tank
<< and properly introducing all
new fish this way will be the surest and safest method.