How do you get applesauce that has stained on the wall out?

Bleach. Dilute some bleach and spray it on, blot it off as much as possible. The problem is that drywall is absorbent so if it got through the paint, the applesauce is there to stay but bleach may lighten the stain. The ultimate solution is that the affected area could be cut out and patched, we use drywall cause it's easy to repair. It may be enough to just paint it.

Wipe with a napkin, or a wet rag, I've tried, relatively easy to use

I would try some washing detergent in a paste with warm water

for me , Wipe with a napkin