I no longer file prep guide feet. For my ocean salt rods, if I use use guides like Fuji's CC models, I don't want to remove the surface that inhibits rust. Instead after I get 5 to 6 wraps onto the guide foot, I'll slightly pull the guide so the foot disappears under the thread. I've also stopped prepping the guide feet for my freshwater rods. I got the idea from rod builder Billy Vivona.