Both hands for me. I watched Lynn's video, and pretty much just do as he does (with a few exceptions). Think of it this way... if you learn to use both hands, you only need to perfect 1/2 as much technique as you would using only one hand. What you do with the right hand, you do with the left. Using only one hand, you have to have two different techniques for both sides of the face.
For newcomers, and those who are just scared to try using their off hand... give it a try. With practice, comes consistency.
Drew