Metalworking, using a grinder
I don't have any problem with your approach, but reading accounts of O Sensei crushing grip by his deshi I suspect there is more than the feeling of center taking in founder's aiki.
There is no question that O-Sensei was strong on a ridiculous level. He was conditioned on an internal level and was just plain crazy strong on a muscular level. Doing something like the famous "jo trick" would take both. One certainly wouldn't want Dan H to get hold of you either... But Dan can do it without losing any freedom of movement, not does he create any off balance in his structure. This is completely unlike what most folks are doing when they grab in Aikido. And, as I said, power put into the wrist, or any other point of contact, may be irritating but has little or no actual function in a martial encounter unless we are talking about strikes, and even then it's a lot more complex than that.