I would also use a paper tiger scorer which you roll over your wallpaper and cuts into it so as you spray the wallpaper and it will penetrate through. Can find at Lowe's.
I've used one part water and two parts liquid fabric softener in a spray bottle as well. It worked through several layers in a 1940's kitchen. Use a metal putty knife to get under it when it's wet and start peeling it off.
I use a 50/50 mix of vinegar and hot water in a spray bottle. Sray it on let it soak for a while. Scrape off with a putty knife.
I would also use a paper tiger scorer which you roll over your wallpaper and cuts into it so as you spray the wallpaper and it will penetrate through. Can find at Lowe's.
Spray on fabric softener like Downey after scoring it...
I've used one part water and two parts liquid fabric softener in a spray bottle as well. It worked through several layers in a 1940's kitchen. Use a metal putty knife to get under it when it's wet and start peeling it off.