never had it happen. I put the plug in fairly loose and turn the crank with a ratchet slowly. it may suck in a little but it makes it easier to blow out. it is also important to have the right size plug. err on the side of a little too big.
I do also use the plug with the outer lip that is bigger than the insertion diameter.
Need a pic
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.