There is really good discussion of the technique here
The way I've always practiced and done it is to ditch one pole as soon as I know I'm not stopping anytime soon, grap the remaining pole with the other hand right above the basket, slide the pole hand about 10 inches above the basket and press on it with all of my weight. I have it in up by my shoulder and always try to get my skis downhill, you don't want to be sliding headfirst even if it means risking a cartwheel.
Never used the Whippets myself, but a buddy uses almost all the time on spring tours and says they're really easy to use. He also says he HAS to wear his straps with them because once you dig them in, they try to twist away. He fell on some relativly mellow terrain, just rolled over and dug both picks in. Looked really easy, but of course there's always the risk of impaling yourself (main reason I haven't tried 'em).
If your're skiing the kind of stuff where a self-arrest might be required, I'd recommend that you find a steep, out of the way place with a safe runout and practice until you can almost do it by reflex. Might save you some day.
Hope this helps [img]smile.gif[/img]