A woodburner would be nice, but I'm nowhere as serious as you are, plus I wanted to keep it cheap, hence me looking for the flat file instead of buying a new one. Figured I'd just bevel the edges that are overhanging and then burn it with a lighter to finish it off.
Having done grip jobs on most my decks for the past few years, I'd be interested in seeing how those carpet patterns come out, hopefully with some insight on how to do them also.