For those of you that think Sky Bind provides incinerating string burn, you haven't tried Swell. It hurts.
Overall, Swell is a sort of awkward trick. It's not really like any other trick I can think of, although maybe you could compare the movements to the movements of Boingy-Boing. It does seem to me, however, to be most aesthetically pleasing when your yoyo is moving as directly straight up-and-down as possible. Good luck, don't burn your hands off.