The McD machine cleans itself by heating everything (machinery and dairy mixture) internally above the pasteurization temperature and then quickly cooling it ba

The McD machine cleans itself by heating everything (machinery and dairy mixture) internally above the pasteurization temperature and then quickly cooling it back down. Kind of a different animal than flushing coffee grounds away with hot water. I did a proposal for some engineering on one of those automated froyo machines. Most are just a dirt-standard freezer with a robot cup handling & topping dispenser attachment. There was no requirement for self-cleaning. And, judging by the finished ones I've seen in public, there's no way I would ever eat out of one of these. I would be surprised if they're cleaned up more than once a week and everything in that chamber is at ambient temps.