Dif Wallpaper Stripper bills itself as "The Only One That Really Works." Well, it didn't work for me. When I recently decided to strip the wallpaper in a half-bath, I knew it was going to be difficult because our builder did not prime the walls before putting up wallpaper. The helpful guy at Home Depot told me Dif was the brand to get. A friend told me the same thing. I acutally tried two types of Dif, the gel and the liquid. I was literally getting half inch pieces scraped off with my fingernails. I tired scoring the walls, applying the Dif and letting it sit for a few minutes. Still incredibly difficult. I won't be purchasing Dif again.
By the way, I've learned the secret to getting off obstinate wallpaper. Mix up equal parts of warm water and cheap fabric softener, spray and peel. Works like a charm!