I use a file card and have for many years. The trick is to use it often. I use it after each 4 or 5 strokes and have never had a file to clog. In fact, I have one file, a 10" Nickleson, that I bought in 1978 when I first opened my shop. I use it daily and it still cuts, not as good as new, but too good to stop it from being my "go to" file. Properly cared for they will last a long time, keep them clean, lift the file on the backstroke, and never let them touch another file. I see so many guys just throw their files all in a drawer banging together, makes me cringe. Then they wonder why they don't cut.