And for a slightly different view... On a warm day (so you don't have to worry about the slope icing up, and it's warm enough that your non-cotton pants will dry out), glissading is a lot of fun and a quick way to descend over a thousand feet.
It's been over ten years since I glissaded the slope west of the 99 switchbacks, and the conditions were right: Warm, and ample snow.
We did NOT have crampons on, since we had just descended from spending a night at the summit, but were carrying full packs. However, even in THOSE conditions, one person wearing her full backpack and using ice axe for a brake, did a complete 360 forward roll, but continued on un-phased.
The one thing that might help protect the pants and the wet butt: take along a garbage bag, make two holes at the bottom just big enough for your legs, and wear it on the way down. Ours protected the pants from the abrasion, but snow still got inside.
Watching out for rocks sticking up in the glissade trough is really important. I would hate to hit one and get a bruise, or worse, a tail bone injury. Keeping speed slow enough to be able to stop, or at least roll out of a rock path is important.
But again I stress this: warm enough that you will dry out, and warm enough that there is no danger of ice.
