You need to get out the elbow grease and HOT water. Keep wiping the walls to remove the paste residue. There might be a product that helps take off wallpaper paste--ask at your paint store.

I had a whole house of this in the 90’s! You need a lot of hot water, dawn, good scraper (I liked to use a 4 inch blade! Be careful not to gouge the walls). You will also need a box of rags. Soak in the walls and get to work!

Scraper, rubber variety. There is no doubt gobs of glue you will find once you get the walls damp. It's quite a job!! I used a silicone bread dough cutter. Scrape scrape scrape..it will slough off looking like snot. Keep scraping until you think it's all gone then come back the next day...if it's not all off before you paint you will see streaking in the paint.

As clean as you can possibly get it and then a coat of Gardz to lock down residual glue for good measure. Wallpaper paste can play havoc with paint.

Once you get the walls all nice and clean, then paint them with gardz primer, to keep anything you might have missed from bleeding through. Then, you can paint it any color you need. It is worth the extra work, to scrub, even though it seems like a big job.

I had to do this in a bedroom - just as people said, hot water, scraper, a separate container to scrape the residue off of the scraper, sponges, rags. I used DIF wallpaper remover; I've also read that fabric softener and dish detergent work well.

Once you get paste removed, you will want to patch the walls with joint compound or spackle to get them flat. It may take more than one application and a little sanding. Then you would put on a primer/sealant coat, like Kilz.

Hot water with a bit of Dawn sprayed on the walls then loosen with a scrubbing sponge before scraping off the mess. Wash the walls until they aren't sticky which will take at least two rounds. After you wash the walls a second time, you can rub your hands on the wet wall to see if they are still sticky. Then as others have mentioned be sure to prime to seal the surface in case you didn't get it clean enough

Thanks so much for all the advice. I took the wallpaper steamer to warm the residual glue and then used a spatula to scrape off the glue and can already see it making a difference. (Though what a mess to scrape the glue off the spatula!). And appreciate the suggestion for follow up scrub down after the first pass. That may be what is needed to make it clean, especially in the corners which are hard to get to otherwise...

PS does anyone have a good tip/method/receptacle to clean off the slime from the scraper while working?

That’s why I like the blades! I just toss them!

I would try a drywall mud pan for cleaning the scraper.

Easy to hold in one hand with scraper in the other.

I don’t know how I would have gotten through the wallpaper nightmare in the 90’s without my grunge and metal😂

Thanks again so much for all the advice. Indeed we used the hot water+dish detergent solution in a spray bottle to loosen and then scrape off the glue, followed by another scrub with more hot water and sponge. What a job! And after I read Lyndee's comment to my husband, he pitched in so we got one room done this weekend. Two more rooms to go but at least I think we know what we're doing...

Yay. One room is better than no room. Good for you.

That is such a charming space! Is that unpainted plaster under the wallpaper? My previous house was built in 1931 and we put the first coat of paint on the walls after 75 years of wallpaper.

@Lyndee Lee Yes, it's unpainted plaster underneath. It's in pretty good condition after we scraped it clean. Our house was built in 1949 so this may also be 70+ yrs old...