I would guess that if a tumbler can do as good, enough better, of a job than what a wire wheel can do then one would probably consider it. The only negative part regarding a tumbler is what else can you do with it, how often will you use it and how much does the media cost that wont hurt the threads of the bolts you are cleaning.
For those with limited shop space I think a small bench grinder is the way to go. While cleaning up my parts I found some goughes in some metal parts which I was able to grind down using the other spinning stone wheel. Wish I bought this grinder years ago.
Craig
My '50 Chevy 3100 5 window, '62-235cu, 3:55 rear
My truck ....... Respect The Rust
If I'm not working on my truck, '65 m00stang or VW camper, I'm fishing with the wife or smoking Salmon.