Most of the wheel building resources I've come across mention destressing by pressing down on both sides of the rim, rotating a few degrees, and doing it again. I turn the wheel over and go around again. I use a block of wood on the bench to protect the axle and bearings etc. I've done it many times and it seems to allow spokes to unwind; I put the wheel back in the stand and continue truing. That's cool.
The instructors at the coop and the owner of the LBS both insisted that if I do not have the "6:00 O'clock position" of the rim supported on the floor, I was risking trashing my rim...?
This doesn't make sense to me. The spokes are already under a fair amount of tension on both sides and if the wheel was going to taco, it would do so whether or not the rim touched the floor at 6:00.
I have over tensioned wheels, but I've been able to release them, start over, and get them dialed in.
What do you think?