The transmission/ gear box on my walk behind mower calls for Bentonite Grease, is there any grease out there that I can use instead or cross references this Bentonite Grease, everytime I need some I have to go to the commercial lawn mower place and buy a tube for $13.00, am I stuck using this stuff, any help would be appreciated. The walk behind mower is a Ransome Bobcat with a Kawasaki Engine, it is basically a commercial mower with a velke behind it.