Except it works on UDP and not TCP.. TOR does not work on UDP, there are things besides http that exist on the internet https://en.wikipedia.org/wiki/Internet_protocol_suite
I don't really understand why OpenBazaar would use UDP, and I can't seem to find any information about it, but it looks like they tell server operators to open up both a TCP and UDP port. I guess they might use it for DHT control messages? Their documentation site is down right now, so that's the best I got.
https://github.com/OpenBazaar/OpenBazaar-Server/issues/240
https://github.com/OpenBazaar/OpenBazaar-Server/issues/202
https://github.com/OpenBazaar/OpenBazaar-Server/issues/164
The server would need to be re-written for native support since it uses UDP, but I think it might be possible using a 3rd party like onioncat.