The first handle got too chewed, so I bought a second one and sprayed it liberally with bitter apple, which the people at the pet store swore would prevent The Mutt from gnawing on the handle. They lied. She had the door open the next day.
So Diana got a third handle. Hot chili oil should work, right? So I wiped down the handle and held it out for The Mutt to sample. She tasted it, licked her chops for a minute, investigated a bit of lettuce on the floor. I expected her to suddenly dive for the water bowl or something, but she came back and started licking the handle again. So..."we haven't failed, we've found 586 ways that don't work."