Clint,
I think I would seek "higher" guidance.
Honestly, if you have tried those items, it looks like it is insoluble after it dries. That means mechanical removal...freeze with an ice cube and scrape off. Try wearing a pair of nitrile mechanics gloves overnight...sometimes the sweaty hands syndrome will break the bond.
Good luck...I hope your formal function isn't a marriage ..."who is this guy, a mechanic?".
Stuart
