I think it would help to know the original poster’s motivation. If the goal is to keep some fancy cycling shoes clean, OK. I wouldn’t care, but I guess some might. If the goal is to keep your feet dry, I don’t get it. I’ve done plenty of gravel races that involve portaging my bike through streams, which then means riding many more hours after soaking my feet. I never even notice it. Ditto when I’ve been caught out in drenching rains.