Hi Don, You should buy a pint of Historic Timekeepers Concentrate for only around $9.00 from Timesavers.com parts house. This solution if very safe to use in your ultrasonic cleaner and does a very good job. After cleaning the parts , rinse in hot tap water then give them a quick dip in denatured alcohol. Use a blow dryer to dry them off or a drying box and there you have it. I would have to say that something in the brass cleaner is causing the discoloration. Good luck Hope this helped.