If its hard to take off then dont bother it will overgrow with coraline eventually. To me I dont think its a make it or break it problem. The last thing you are gonna want to do is screw up the tank and then have to go find another fast.
Just use that in a well ventiladed room, wear gloves, and dont get any in your tank. Xylene can soak into your skin and cause problems with your nervous system.