Ahahaha! I totally shocked Huey last week! I was hanging out in the paddock with him and realized he'd been turned out with both his rain sheet and his fleece cooler on, and the barn staff hadn't come around yet to peel the horses, so I shucked his clothes. I have LOADS of problems with static in the winter - I can't get in or out of my car without shocking myself silly on the frame, it's so loud that everyone in the car can hear the ZAP! - but I wasn't thinking, and I pulled his fleece off, tossed it out of the paddock, and turned around to give him some Horse Muzzle Love. And zapped him, good, right on the cheek!
He shot up in the air about a mile and ran to another part of the pasture. I decided the best thing to do was to hang out, looking unconcerned and peaceful, and wait for him to forget about it all. That took maybe 5 minutes before he drifted back over for his scratch.