That’s what I bought. I keep a soft drink bottle mixed and handy. I wipe down my signs right after cutting. Takes off the mill scale and the water tray yuck. Then a quick wipe with some biodegradable paint thinner and its pretty clean. Dross either by hand, brick chisel, or flap disk as needed.
Sometimes I use a scotch scuff pad before painting, but I have had pretty good luck just painting after that routine. Of course, I’m talking just spray can painting, not anything fancy.
I agree with everyone on the bristle brushes being effective, but I’ve been stuck by the flying wire so I only use occasionally.
That is my issue with the wire wheels. I wear a Carhartt jacket most times and there is usually a wire or two impaled in the fabric after using them. I have read that fine slivers of metal are found in the eyes of workers who use such equipment and never felt a thing. Be sure to wear good, wrap around eye protection with those wheels.
I personally have a big flat Tupperware container with 5 gallons of vinegar in it straight from the grocery store. I typically leave parts in there for at least four hours and the mill scale rinses right off. Even helps loosen the dross.
The best way to remove dross is to forget you put the parts in vinegar and leave them there for a couple of weeks. I cut some of these parts and was dropping them into the vinegar when I heard them hit something that was already in there. I pulled them out, rinsed them off and zero dross left. This pic is of the bottom side of the parts.