The fellow doing the chrome for VDH has recommended nitric acid as being safer for chrome that vinegar, etc.
Vintage Double Hose :: View topic - GD Corrosion Remover
I still use vinegar (have been using it for close to 40 years), but I limit the exposure to less than 15 minutes (in pure white vinegar). Normally all the corrosion is gone in the first 5 minutes. If there is any verdigris left, it is probably being shielded from the vinegar by other contaminants, in which case a bit of tooth paste and some scrubbing with a tooth brush seems to do the job.
I once left by accident my Scubapro 109 in vinegar for a few hours (when I was working at my LDS back in the 70ÃÔ) and it did eat some of the chrome on the inside of the regulator.
I have an ultrasonic cleaner, but after some recommendations, I will not use vinegar in it. I am thinking about other cleaners, one recommendation was Blue Gold.