I use regular dish soap to wash my apples and other hard produce, yes. Works a treat, but a dedicated fruit/vegetable wash (“Fit” is an example brand in the US) works too. It may leave fewer deposits/less residue, no idea, I haven’t looked up any papers on it. The main reason I started was even rinsing my apples with water alone, I’d notice a chemical taste on the skins which is very similar to how the produce stands at the supermarket smell. Washing with soap gets rid of it, as long as I make sure to get the crevices at the “poles” of the apple.