I have the Castle Bay soft plastic one piece slip ons on my old DCI's. I wipe the club after each shot and they are stainless, so no problems with rusting in 19 years and my DCI's look new. When I pull the club, I stick the cover in my hip pocket, after the shot I wipe the club and stick the cover on. If I am not driving, I may do this while riding to the next shot. It takes 5 seconds and does not slow down play. I understand your obsession and have a set of 30+ year old Wilson Staffs that would pass for at least a 2 year old set.
That said, my "new" walking set is pre nicked and I do not use iron head covers on them. I must say I enjoy the freedom!