I used to use a old toothbrush & bandana kept in range bag tool kit; got old fast when used during a match. still have 'em in the kit, but now kill two birds with one shot by reloading with retention (spent mags) keeps mag clean and good practice.

I shoot BUG DIV. w/CM9 (EDC) so most of the time I don't have to do a reload with retention like other div.(revolvers get break also) as I'm at slide lock after 6rds.
maybe during a sanctioned match for the marbles I might get gungie