For me, I'd pick one of my all-time favourite tools "the poor man's sand blaster" I call it - a cheap angle grinder with a rotary wire mop. Cleans rust, paint, you name it right off anything, and produces very little abrasive by-product. I use mine all the time. The only thing it can't do is get into tight spaces. For that I use a cheap Dremel knock-off with a tiny wire brush
Steve.