Excellent for small areas where staining has occurred. Follow advice on the can, spray from a distance and evenly - it will coat the affected area with a fine mist of oil based paint. Do not spray too thickly as the paint may then run. It may need a few applications. In some cases it spread so finely that no other painting was required where the white colour was similar.
Ensure that you have a dust sheet underneath as the spray may end up on the floor beneath whatever you are spraying.
In my opinion it is better than some of the other products on the market.