Sam4: It’s an entirely different type of issue. Assuming there is no inherent Issur of being Mevatel Lechatchila (some seem to assume there is but Pashtus is like that; Pashtus is that if I am intentionally Mevatel something that I’m going to throw out anyway there is no problem) so even though there is a P’sik Reisha that it will become Mevutal there is no P’sik Reisha that an Issur will be done.
Igros Moshe YD 2:24 goes to great lengths to prove that the Shellac is Muttar beyond a shadow of a doubt.