There is absolutely nothing about callous that will make you hit or grip harder. It may help you keep from getting bloody knuckles, but that is literally all it can do. Plus it can look kind of gross depending on how much callous you have. Don't waste your money on useless crap. Your hands will develop all the callous they need from training.

If you want to hit harder, then keep on practicing your strikes. If you want a stronger grip, then develop it with grip training. Having stupid looking, white, flaky dead skin on your hands doesn't contribute to your fighting skills at all.

"Ancient Japanese secret."

You'll never know until you try it.

someone got ripped off. wtf? rub the oil on your body. the whole bottle.

That sounds good but becareful what you ask for the more you practice martial arts the more they make fun of you because you visions become true.

I bought this oil from this man at a tournament because he said that it would build up my calluses to make my strikes and grips harder in Hapkido. He said it was an old Japanese secret and that his family been making it since the days of the shogun. It was $25 for 6oz. Does it work or not?