We hiked into Icebox Canyon one day, looking for shade and cool air, with guidebook in hand. I was able to identify Frigid Air Buttress and a few other routes; some day...
To the left of Frigid Air is another good looking line called Burlesque - this is also roughly the descent line off the Buttress. I think the key to make this descent less stressful is to have double 70 meter ropes (also, some daylight wouldn't hurt....we should've gotten up ealier for this one :)
The descent is also possible with double 50m ropes.
1. Rappel the chimney with single rope from the chock stone.
2. Follow cairns to get to the tree at the cliff top. Getting to this point involves exposed down climbing at times.
3. Single rope rappel from the tree to a large ledge with single bolt and rope slings around a block.
4. Double rope rappel and locate slings on your right (rappellers) in a corner on a slopy ledge.
5. Double rope rappel to another big ledge with tall bushes. Walk left (climbers) and locate slings around a tree and boulder.
6. Double rope rappel into the wash.
7. Walk down the wash and go on either side when the boulders become too large.