Any one have tried to stretch ( widen) a set of fins?? a set I bought fit fine longways but I have Fred Flinstone feet and they are cramping my feet. Avanti tres..."warning "on side sez keep temps below 167 degrees as they will stretch...I thought putting a stretcher inside and hot water over the area might solve my tightness issue...anyone ever done this?? as I dont want to throw away the $$$. Don't want to send em back for the xxl as these fit fine for the length just tight on the sides....:06: