Worst case of galvanic corrosion I have ever seen was in my work, on machine that grinds rotogravure printing cylinders.
Machine´s outer panels are made of stainless steel and those cynders are mostly copper, that grinded copper goes sometimes to contact with stainless steel and there are also water in system for coolant and lubrication. So if you leave that copper dirt lying over those stainless steel panels thay will corrode into it and then you cand remove it anymore, a week seems to be maximum time between cleaning machines stainless steel panels.