fschifano
Member
You're right, of course. Detergents are there to dissolve oils and fats, none of which are present in photo chemistry. I can see where they might make a bit of a difference if there is an oily film deposited onto the hardware from an airborne source. Soot from an oil or coal fired furnace could do it, and in fact, did in my case. That old and creaky oil burner is long gone though, having been replaced with a much more modern, natural gas fired unit, and with it the problem which affected the entire basement of my house.