Apparently Muslims teach their hildren to wipe their butt with their left hand and eat with their right hand.  The left hand is the "unclean hand."  But let's get real, parents do not want to teach their kids which hand to use while masturbating and kids don't want their parents teaching them which hand to use.  So, kids are going to masturbate with their right hand which in turn makes the right hand unclean.  It's a lot easier to teach kids to wipe their butt with their right hand and eat with the left hand.  Much more practical.  Problem solved.