Or get a garden sprayer, mist the walls very lightly, by the time you have worked all the way round the room the first lot will have soaked in, go round again, and again, and again, until the paper in perceptibly wet (but preferably not running off and into the floor.
Go and put the kettle on, then do it again.
Have your tea, then do it again.
Concentrate on the top of the wall. Once you have started scraping it from the top, spray on the bare plaster and it will start to run down behind the paper and work faster. Don't let it dry, keep wetting it.
Add half a drop of WUL per gallon to help it soak in
Use a scraper to roughly knock off as many of the scabs as you can first, because this will break the paint film and help the water soak in.
A steamer, if held in one place for long enough to make the plaster hot, can cause it to crack and blow off the wall.
When you have stripped paper, mist the bare wall and use your scraper. It will take off a wet sludge of old paste and fragments of paper. Do it until the scraper stays clean. Paint will not stick to glue.