(Update) Fridge Maintenence ? Who ever Does That ?

I had lunch with a friend today, and yesterday he took his 5th wheel to an RV shop to have his propane water heater and refrigerator looked at due to black streaks appearing on the exterior of the RV and poor performance. The repair guy used a compressor to blow air into each compartment and clean the orifices. It took about 5 minutes and everything works fine now. I'm not sure if they actually charged him? JR RV Repair in Sedro Woolley, WA is like that.