Pom Pom Crabs aren't really clean up crew, they don't do much, they kinda just hide all the time and mop whatever comes to them or floats by. If you like them they shouldn't harm anything and the sting is so minimal to most healthy colonies it bumps. Can't promise you'll ever actually see it...
...times.
Step 8. Dream up some explanation of why it looks like it snowed in the tank to tell my wife. Then act surprised when she says what the #@$%#@$ happened!
Step 9. Count your luck stars no corals of fish perished, no chemical burns on my hands and still married.
Step 10. Don't try this...