oh, I was picturing caked on dust from being outside.
Anyways, yes, I do use soap... Yes it can leave a head killing film... No I've never had that problem cause I'm cheap and don't care if my glasses are spotty. It's the anti-spotting agent that causes trouble, so use the cheap stuff. And I run the bottles a second time without soap right before bottling so they are rinsed clean, sanitized, and ready to go. I even pull the dishwasher rack over the the bottling setup to make things quicker and easier.... Of course this is only when I bottle, which is rare these days thanks to kegging