They landed with much fanfare here in the early 1960s. Many coin laundry suppliers introduced them in their coin-op stores: Philco, Whirlpool, Frigidaire, Norge and later, Speed Queen. They were sort of triggered by the invention of washer-dryer combinations, except in the case of Frigidaire. In those days of cheap petrochemicals, you could do an 8 lb. load for $2.50. Often, finishing in a steam cabinet for about 50 cents extra was needed for best results. This was at a time when coin washers cost 25 cents a load and the dryers were 10 cents for ten minutes. A lot of people used them. There were some problems with clothes that were not properly aired after the cleaning including the tragic case of a child who died on a family camping trip in a sleeping bag that had recently been through a coin-op dry cleaning machine and then just packed away. They needed expert maintenance and used toxic chemicals. There were cases where the "Perk" leaked into the air of the laundry during the last minutes of the drying process (when the air in the drying chamber with small residual amounts of the solvent was vented outside) and combined with the gas flames in the dryers to produce compounds that ate holes in the clothes as they dried. The one thing that they never proved to be was "self-service." There had to be an attendant on duty. All but the Frigidaire machines used one machine for the process. Frigidaire used two machines in a cabinet, a "washer" and just above it and at a right angle to the "washer", a dryer. Because the items had to be transferred from the "washer" to the dryer while saturated with the Perk, the ceiling of the cabinet housing the dry cleaner concealed a very powerful exhaust fan to keep the operator from inhaling the fumes. I still wonder about the long term health effects on the attendants, especially the ones who smoked. The "washer" part had a lid that could only be opened with a key and the dryer door might have had an electric lock. I just remember that if there was not an attendant present, it could not be opened or used.
The last time I had any experience with one was in the late 70s when I took a wool coat to a place that had the WP machines. The price was up to $10 and they were behind a counter. The lumpenfrau attendant brushed off my interest in watching; just told me to come back in an hour. Having had a WP combo to play with a decade earlier, I was interested in seeing if the dry cleaners spun faster than the combo and if it would even spin at all with only one heavy coat in the machine. I suspect she knew there should be other stuff in with my heavy coat and did not want me to see that customers who paid $10 for a load had their stuff combined with someone else's for a new spin on being taken to the cleaners at the cleaners.