We have a plastered interior wall that we have been very pleased with; the plaster is instead of painting on a regular gypsum wall. It has worked great for over 5 years until I poured sesame oil/cooking oil on the wall, don't ask why 
Now there's a big grease stain that has run down and can't be removed, so the only solution seems to be to apply a new thin layer of plaster over the entire wall.
I've painted before but never plastered, so a few tips would be great since my wife isn't too happy with the stain. I'm planning to try to fix this over the weekend.
Now there's a big grease stain that has run down and can't be removed, so the only solution seems to be to apply a new thin layer of plaster over the entire wall.I've painted before but never plastered, so a few tips would be great since my wife isn't too happy with the stain. I'm planning to try to fix this over the weekend.
the fat could get through the new plug.
also, there may be problems with fastening
also, there may be problems with fastening
You can try cleaning the plaster with an ammonia solution in a spray bottle, 10-15% mixture. Personally, I have managed to remove a couple of grease stains on an absorbent surface. Naturally, it depends on how much and how deep the grease is. Regardless, you need to clean if you're now going to try plastering over it, and the spray works well for that too.