Give them an ouchi owe-E
Did you ever notice how the higer ranked teachers make you move like a rag doll?
They start with a little pain in wrist twist, or manipulation, or get you totally off balance ... don't they?
Next time you can't get Shihonage, take the balance with a bit of squeeling pain from nage ... then tell me if they escape or wriggle out?
Many of your warm up wrist twist exercises are the motions you need to affect this pain, use them. Pain is a great motivator.
(please don't break your brother's wrist, or when they ask you if you do'd it, you gonna get a whippin'...)