Hi, Liza. You could have big problems doing it Joe's way. Citristrip or any stripper's active ingredient will soak down into your porous plaster or wallboard. If you go back to paint too soon, it will cause a lot of problems with the new paint.
There are some things that you could try if you do decide to do it that way like leaving the stripped walls bare for a week or two before repainting and washing the walls with denatured alcohol but sanding the old paint off is the surest, safest way. A sanding screen like you use for sanding new drywall joints should make the job go pretty quickly but you will need plenty of screens with the gummy paint and you should not do this if your paint is older than 1972 because of the danger of lead in the old paint.
If you do opt for the stripper, remember to use rubber gloves and good eye protection. And if you use alcohol on the walls, remember that it is flammable and burns with no visible flame. Don't use it at all around a source of ignition like a furnace, water heater, gas stove or electric motor.