I notice on the Acme site that they also offer the C-clamp type that fstbttms shows. At around $30 I'd probably give it a shot. I didn't find anything where an owner said don't buy that thing in looking around. And, it's certainly a technique often used for removing similar items. I wouldn't say Jim's description of irritating it off was correct, more like shocking it off which sounds worse than subsonic harmonic pulsations.
The one site, the guy said don't use a dead-head hammer with it. (there's a name for those shot-filled hammers that escapes me at the moment).
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.