How about smearing a stick of butter with Tabasco sauce or wasabi? All mammals are sensitive to the hot stuff. Of course, some of the folks around here would think that would make a great base for a barbecue sauce. :)
We tried that method with a lab once...she appeared to like the stuff...
I dunno if he’d go for it, though, actually, if it smelled wrong. And he’ll never ever do it when I’m around. If I’m around, he won’t even grab something I drop on the ground or start eating what I’ve put in his bowl unless I say “OK” first. If I’m outside, all bets are off.
It is a puzzlement.