For a low buck guy like me, it turns into a big mess, However, when cleaning the inside of the tubes for reinstalling axle shafts and the like, I have a wire brush cup that I welded to a long rod and chuck the rod in a drill. Then I use a hose clamp on the brush to compress it enough to get it to go into the tube, release the hose clamp and start drilling. It cleans up the inside quite well although I always scrape it as best as I can first with a long piece of threaded rod with a washer bolted to the end and then suck it out with a vacuum after the wire brush treatment. Finally, I follow up with a rag soaked in brake cleaner taped on a long rod. Jeff