I use a spray bottle of distilled water. Spread grains, spray them, mix, repeat two/three times the night before. I crush grains in AM while water is heating, so grain has time to air out and not be wetted in the mill.
The other big benefit has been more consistent traction thru the Barley Crusher. I crush by hand, and it used to spin quite a bit and "miss" stuff. After conditioning, it crushes very consistently.