Replying to How to motivate other people to throw new tricks?

My brother and his friend have spent the last two years talking about learning corks. I mean they have them on lock on tramp and into water. They have lots of control and land every time. They have been hitting somewhat big jumps into both good and bad landings for a while. So when I offered to help them build the perfect jump to throw corks on, we were all pretty excited. It was nice and kicky 25ish footer with a perfect landing zone, about a foot of powder on top of a few more feet of soft snowpack. I honestly expect them each to land it first or second try. But for TWO HOURS I watched them hockey stop on the lip because they pussied out.

No matter what I said, whether it was a tip on the trick or how to stop overthinking, or calling them a bitch or saying you got this, it didn't help. I know the best way would be for me to throw a cork first but unfortunately, I can't be hitting jumps right now. I'm just curious what y'all have had success with to say to someone being a massive puss despite trying something they have wanted for years and you know they can 100% do.