A socket would not work for removal of the anode rod.
What? Every anode I've removed was by using a 31mm impact grade 6 pointed socket. See what I mean about not telling the entire story? So what do you use then to remove your anodes?
The liquid wrench was sprayed into the anode head cavity.
Normal ops here. Don't see an issue. Unless you sprayed several cans and magically it all collected in this cavity as you call it. Never seen that happen. There is a small area where a tiny amount could collect at the threads. Not enough to wreck the entire house hot supply. Maybe your tank is something I've never seen or worked on? Offering you the benefit of the doubt.
We can still smell it in the hot water after endless flushing using various additives.
Are you smelling the upper tank area where the spray was used? Or is it actually IN the hot water?
Take a hot water sample in a glass jar. Take it outside in the wind, far from the house and water tank. IF there is any oil in there, it will not blow out. Should be seen floating at the top of the glass and can smell/taste it. Do a cold water glass jar AT the same time. See if you and the wife can smell it. Blindfold even better.
My guess is that when sprayed, there is a fine mist of oil that gets into the air. That mist can fall on drywall or any other porous surface and create a smell. Wash any drywall down with pure ammonia and a rag. Clean all around the tank and anode area. Ammonia will cut that oil and definitely leave a clean smell.
Shifting gears. I hope you don't drink your hot water regularly. Too many diseases can live/grow in a hot water tank.