Yes they work , I used one for a while but found that it took forever tho melt the wax , I had to turn it on at least an hour before I planned on using it.
Then I found this little beauty at a yard sale , it is a 1 quart deep fryer , will melt the wax in about 5 minutes or less , you have to be careful to set the heat right so you don't start a fire though.
But the crock pots work OK if you don't mind waiting.