In the 80s/90s national team members were taught tumbling at the Olympic Training Center. Dunno if they still are. The "tuck and roll" does work, although I have always maintained that intentionally unclipping in a crash situation is stupid. The idea is to tuck the head toward the handlebars rather than "superman" into the ground and do your wrists/collarbones. The bike ends up flipping through the air.

Preparing for crashing always seemed a bit defeatist to me, at any rate. I'd consider focusing on bike handling drills instead...