A variation of the brass case method is the copper tubing/piping one. Use a length long enough to have a comfortable handle, split one end, open with vise or pliers. This creates a spatula-like tool. The end can be contoured to match the barrel curve. This is also effective to clean files, with the edge flat. It works much better than a file card.

I prefer wood to plastic, leather to nylon, waxed cotton to Gore-Tex, and split bamboo to graphite.