Actually the Amish folks I knew use to turn their evaporative refrigerators upside down on the porch and leave it for a day or two. I'd be careful trying to shock the tubing with a rubber mallet, a cracked coil means a new cooling system.
You'll have to weigh the risks. Tapping might make it work again, OR break it. You'll need a new cooling system if you do nothing, leaving it unreliable.
I'm sure someone will suggest replacing it with a residential fridge, but I understand your model has dimensions that make it hard to find a fit without much modification of the space.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI