I've started using my ultrasonic cleaner - (use it for my brass .303 and .308 usually) for cleaning my cylinder and nipples on my Remingon 58 stainless. Excellent results using white vinegar. For blued cylinder etc wouldn't try it though, however washing up liquid would be fine.
x1 cycle of 480 seconds - great results.
Try Maplins for a ultrasonic if interested I paid £19 for mine. I think it was a second so cheaper than normal errr all that was wrong with it was two of the rubber feet missing.