I got mine done at american laser centers, they are very professional and have a guarantee (i.e. you pay for 6 treatments and if 6 doesnt do it, you can keep going until its gone for good.)
It does hurt a little, like someone else said a hot rubber band. But its the best money I've ever spent. Getting your ass done will be a little uncomfortable, especially because you have to go "between the cheeks" but I'm sure its not the first ass they have lasered. | 
