Hate to put a damper on things mate, but i had a bitch with the same problem, and to be honest, nothing worked for me, i eventually had both stops removed and the skin still split, i wasted months nursing the dog each time the stopper split which would always happen on the first slip, sometimes both stops at once! f***kin nightmare good luck to ya, hope you find something to help, i reckon get a new dog
i hope your wrong, i will be gutted if she ends up like yours. Luckily shes insured so i can try everything to get her sound again.