(cont'd) I was really concerned about digging into the sheath of the drywall. That could make a big mess and would need repair. I bought the cheapest, widest, plastic putty knife for $0.89 and that did the trick. It did not dig into the drywall. If I had used a steel bladed putty knife, I believe I would have dug into the sheath several times. Remember, water is the key. If I had used more water I wouldn't have gotten such a sore arm. Let me know how you do! I'm doing the whole house and I could use some tips myself!!