If I can ask. . . How stuck was the most stuck 
sketch you tried this with, and what level was 
the damage to the sketch once removed?

This one is SO stuck, I couldn't even find a 
place to slip in the smallest blade of my Swiss 
Army knife. (Which is what I usually use to 
carefully cut away stuck sketches since it's 
blade is so fine and sharp.)

Many Sharp Smiles,
--Drac