Hi Sharon. I have "healed" my beads before. I just put them into the kiln and turn it on as you would normally. I wait until the end of my session before I put a bead back into the flame. My beads are very large though, so they take awhile to heat through enough so that they won't explode in the flame. It works fine unless the crack is a compatibility issue.
Oh, and I meant to say something else. Implossion beads I have issues with. They tend to be very sensative to cracking. I have yet to figure out why. It's been driving me crazy though so if anyone else could chime in with a thought about this, I would be a HAPPY girl!