do you wash ACF off every time you've been out?
Yes, but I don't go out that often in the depths of winter so it is not a huge problem for me.
I have a science experiment in the back garden, an old shelft bracket I rubbed down and applied a thin film of ACF to one half and none to the other and put jammed it in plant pot outside, after a couple of weeks with some rain even the ACF half has started to rust, the non ACF half is MUCH worse though, but it made me think perhaps spray from the road will blast ACF off over time.
Went with the cold hose down, apply cleaning product, second cold hose rinse then dried off most of bike with a cloth and put back in garage, will just put some ACF on a cloth and rub around areas that spray will hit - behind front wheel (Engine / Exhausts) underside of bike (Swingarm, Bash Plate etc)
Going to run a new experiment next using ACF on one half of my metal bracket and WD40 on the other half and throw some salt on to see how they compare - gotta pass the winter weekends somehow.