I've been fighting with it now on my 1/32 HK P51d build to see if I could get a good nmf with it.
After weeks of trying various techniques I settled on painting it over a coat of alclad. By varying the amount of polishing you can get interesting tarnishing affects over different panels. But it is a lot of heard work to get acceptable results. Probably will work better on small parts unlike my p51 wings.