Solutions to Problems electroplating silver onto copper bus bar

I work for a company that builds transformers. In the past we used a rub on powder to silver plate bus bar that had to be plated while physically attached to the unit. Over the past two years we have been trying to electroplate silver-cyanide using a portable machine that uses a brush wand. So far we have not been able to consistently keep the plating from turning green. Of course, we don't ship out any units without successful plating, but it sometimes takes several attempts before it "works". The most recent method we've used to try to clean the copper is to buff the surface, clean with a metal cleaner call Q-Brite, either wipe off or dry the cleaner with a heat gun ⇦ on eBay or Amazon [affil link] , plate the surface, then wipe off or dry the remaining silver-cyanide solution with a heat gun ⇦ on eBay or Amazon [affil link] . Are there any methods to help the results be more consistent without using any sort of dip tanks?