Rich,
I use a “homemade” solution to rust chain for my military flat car tie downs. Place in a plastic tub you don’t mind losing:
2 cups hydrogen peroxide
1/4 cup vinegar
2 tablespoons table salt
Place your to be rusted item in the solution and let it sit for 24 hours. If it’s not rusted enough, put it back in for longer. Obviously, you can proportionally increase the amounts if you need to treat a larger object.
Hope that helps.
Price