Ultrasonic Parts Cleaner Removed my Chrome Finish

If its one thing I like to share its my mistakes (so hopefully some one else does not encounter it). I tried out the ultrasonic cleaner on my AR15 bolt the other night since I heard it cleans them very well. I dropped it in and went onto my chores and getting the kids bathed and ready for bed. When I returned to the bolt, it was clean. However, the ultrasonic cleaner had removed some of the Chrome plating and the bolt began to rust. Only after an hour and a half. I had also heard that of you put multiple parts in the cleaner, that the vibration the ultrasonic cleaner produces on the parts can rub the finish off if they are touching each other. Not sure if this is true but after seeing this, it might be.