Brightener for carbon steel

Hello all, Newbie here. I restore old machinery, lathes, mills, etc. The non plated carbon steel items, handwheels, levers, etc. are discolored from rust. The scotchbrite or steel wool treatment does not get all discoloration. Does anyone know of a brush on spray on treatment similar to liquid brightener for aluminum that will achive the same result when used on carbon steel ? Thanks, Larry