I have never heard of a beardie being probed! The best way to determine the sex of a baby is to buy a sexable juvenile! When probing small snakes the usually wait until they are a little larger, and even then they have to be very careful not to hurt them. I would not probe a beardie, I'd be afraid I'd puncture something! (I'm not sure that it is physiologically plausible anyway)
As for cleaning I use a 1:2 ratio of Listerine to water. (I buy the generic brand!) It doesn't hurt your animals and kills any germs that it encounters. It isn't as harsh as bleach and will not burn your animals skin. I use this to clean all of my cages (snakes, beardies, etc.) and use it to clean the enclosures of a few rescued animals who had open wounds. It works beautifully! (And, it won't leave white spots on your clothes!!)
Good Luck!
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Kelly Affonce
DeKeaff Exotics
AIM: DekeaffGrrl