Yea, you can absolutely use a wax heater. There are also heaters specifically for incense (they can usually achieve higher temperatures for heating woods), and tealight heaters. I also use an MHP30 mini circuit board heater. The traditional way is to use charcoal, but it’s a pain and a bit difficult to get the temperature right.

And you’re right, the heated varieties don’t usually seem to have much junk in them, especially as they aren’t a very popular category in the west.