Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
I have blades that have never been without ink on them, I am sure I am the only one. I don't have time to clean ink off blades all day. My whites, reds, and blacks are always covered in ink many others are color changed for the next job. (process inks get cleaned right after the job just because they will not be used again for a while)I don't see the concern. I have some 4 year old blades that are still sharp and have no noticeable strength (duro) or print ability loss. I have new ones to compare them to. You don't make any money cleaning ink off squeegees. Print more clean less.
Our smiling jack with black ink hasn't been cleaned in over a year and this discussion made me go out and clean it and compare it to other SJ's that are cleaned after almost every job and there is no noticeable difference that you can tell by eye. I also have a durometer tester and they all read the same and look identical under a loupe. Our blades for white are rarely cleaned either and I analyzed them as best I could and saw no adverse reactions to the ink. I don't doubt that this still happens from time to time, but I feel certain that it hasn't happened here at our shop with our blades.