Cleaning C260 brass

I have C260 brass parts that eventually have to comply with FDA regulations for breathable oxygen. I need to remove scale/tarnish created in the annealing process without scrubbing the items. We are using an acetic acid ⇦ on eBay or Amazon [affil link] now, but finding that it is leaving a residue on the parts so we are creating another problem and it isn't really cleaning them all that consistently. Is there another solution we could use that would be compatible with a type of ultrasonic cleaner or dip tank environment?

Thanks,

We clean brass tubing using the acetic acid method. After cleaning we rinse in a bath consisting of a weak solution of lye (about 2 tbl spoons /gal water) and then rinse with water. This will remove the residues of the acetic acid which if not removed will cause corrosion/tarnish.