Not sure what the Shop Foreman did that was lacking? Unlike in a medical setting, the gloves are more for the protection of the wearer, not so much for the cars. It's not like he is going to cross contaminate that white car in the next bay.
With oil changes, I put on one glove to twist off the oil filter (that is facing up). Otherwise I wipe my hands with shops towels. There is also cherry hand scrubber for hard working hands... Oh wait, I get it! He can't stop talking. 
I have seen someone here change his mind about spark plugs, on his own, not by any particularly strong arguments presented to him or annoying pics of messed-up plugs that I posted. A shorter OCI may be a good idea when the time is right. For my highway commuter, it's $50 ($35 oil $15 filter) every three months (6K miles) or $16/mo. I call it 50 cents per day.