Yeah that's a cardinal rule of glissading. Never, ever, ever glissade with crampons on. And when I was taught to self arrest with an ice axe (meaning if you were to fall with crampons on) you go onto your stomach and bend your knees so that the crampons are out of the way.
While I've glissaded with trekking poles they really aren't designed for that and you could bend a pole. Nothing beats an ice axe if you've taken a class to learn how to use it.
Someone just posted some photos of someone glissading in shorts. Brrrrrrr.
Ellen