Maybe someone else will chime in here but I think the concencus would be to LEAVE IT ON UNTIL IT GET LIKE BUDDA.
Take it off too soon and the collogen (sp) will not have broken down and it'll be tough.
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Orange Super-Duper Fast
'08 Weber Genesis Gasser
SJG Tamale Pot Mini Smoker (SJG was a rescue)
and a Pyro FIL