good idea: gallon of sheetrock all-purpose pre-mixed joint compound. aka mud.
bad idea: gallon of ultra-strip ultimate paint remover.
except for paint stripper. the wonderous gel formula is supposed to be ideal for vertical surfaces. let sit 15 minutes and scrape away 1-4 or up to 25 layers of paint! environmentally safe! non caustic! odor free!
i am still optimistic that my dark brown trim paint [matches ikea black/brown] will cover any and all sins. and thankfully, i only bought the smaller quart sized container of paint stripper.