Ok, tried just the hairspray, but there's just too much wiggle room between the grip and throttle sleeve so it just slid right off again. Gave up on the hairspray and went with the grip glue. Yesterday while on a group ride, the grip glue started loosening up. Managed it until I got home, removed the grip and grabbed some self-vulcanizing rubber tape. Cleaned the throttle sleeve and grip of the old glue, wrapped one layer of tape around the sleeve, sprayed a good amount of hairspray and shoved it on - now we're solid.

So, combine self-vulcanizing rubber tape and hairspray. Maybe I'll suggest this to the wife and daughter for those bad hair days.

Speaking of which, anyone need a free set of stock Valk grips? They're just in my way and I'll send them for free. They are in pretty good shape; that is, the clutch side is fine, the throttle side sustained a little damage when I was removing them. The threaded stud of the throttle sleeve is still in the end cap of the grip. Whoever installed the grip got some glue in the threads, consequently when I removed it the threads broke off. I'm going to post this in the classifieds; first responder to my email wins.