I've never hot knifed, but after reading about it I thought of an easier / safer method. Instead of two knives why not just use a pait of scissors?
Has anyone done this before? Seems like an effective method for not burning yourself; and, it would eliminate juggling two knifes and a cup.
Not sure if it would work, but someone should try it and give us some feedback! I'm dry so I can't really test it..