Bollocks!
180 grit for frets is well over the top. 240 at the most for bad frets. If you need any more than that you need new frets. Also crowning files make more mess than anything else. A file with the wrong size slot will f*** you right up.
All you need for fret levelling is a 24" straight edge to make sure your neck is flat in the first place, a flat piece of something (this much is correct). I plane a 6-8 inch piece of scrap for this. Tape off the board inbetween frets, Mark the frets with permanent marker, scrub (sideways) with 320 grit on your flat thing until there is a shiny crest on each fret.
All that is left is to 'polish' the frets which also recrowns them at the same time. Starting with the 320 polish down one side of each fret and then back up the board on the other side of each fret. Repeat this step through grades of wet and dry 400 up to 1000 or more (or indeed less) depending on fret material as some require a finer polish than others. Finish with fine wire wool and you're done. I used to buff with compound but I do find that it is totally unneccessary. Remove tape and lightly clean up the board with wire wool.
Fret levelling is a coupla hours work at the most and really very simple to do well.