I need the secret to remove 20 year old textured wallpaper.

sorry having done this when we bought our old Victorian home is using a rented steamer. Then sand after removing the wall paper and wash the walls good and then go ahead and paint them.

I used cheap diluted liquid laundry softener in a spray bottle (messy but does the job)

I have removed a LOT of different types of wallpaper, and have found this to be the absolute easiest method. Get a good quality, large capacity squirt bottle (you’ll use it a lot, so spend an extra dollar on this). Starting at a corner or intersection, squirt about 5 square feet, all over the top of the wallpaper (even metallic and vinyl). Let set for about 15 minutes, then repeat, expanding the area you squirt. Now, with a large putty knife (I like to work with a 3" blade and a 1" blade) hold it next to the wall and gently lift up a corner of the paper. Using fingers, gently pull a large strip off. Continue as you are able, spraying in advance. Once you get started, it comes off very quickly. Use the scrapers to remove little patches of paper. Finally, wipe down the wall with a rough (like terry) cloth to remove extra wall paper paste. As a reminder, wall paper paste usually has pesticides in it, so be sure to wash your hands when finished or use gloves.

Rent the steamer and scoring tool. Run that little hole poker all over your wall, and when you think you have done enough, do more. Wet the wall slightly and use a steamer. May take a bit of time, may come off in layers, but eventually it will come off. Good luck!

I've read that using liquid fabric softener in the water works, tho never tried it myself. Also, have you scored the paper? This sounds like such a job that I tend to avoid wall paper like the plague.

I used this method, adding fabric softener to the water, made it much easier to remove

I hope my 43 year marriage can handle it!