Yeah, I had a fella "break" me of that habit years ago. "Oh, that's why you don't do that... Damn. Hold on, I'd better tape that finger to the other one and hit urgent care..."
Lots of folks' first reaction to something like a sankyo is to try to grab at their hand if they can get there. With a finger sticking out it's the first thing I'd go for myself if I could. Fingers make great motivators.
Yep. As a person with small hands myself, I've been taught that sankyo can be very effectively applied just by holding uke's pinkie...darn if I want to offer the gift of a "handle" myself!