I've been creeping around zapping sleeping people around Markarth but nothing has changed. There's a message that comes on my TV every time I use it on someone who is asleep but the beginning is cut of because it's off screen and it disappears so fast I can't figure out what it's saying.
"Since everybody here is deadset on not being intelligent, let me start things off."- SterlingFox
I haven't messed around with it, but I have to assume it is similar to Nimara's ring. If so try having it equiped and pickpocketing a sleeping person to see if there is a box that pops up to ask if you want to recharge or loot.