Using the firewall to force dns because the services were stupid enough to rely on dns to determine location. You would use a (usually paid) dns service hosted out of the wherever the content you want was and get access to region locked stuff like the US netflix library from abroad. This worked because vpns were being detected and rokus dns was hard coded so assumed to be trusted.
I don’t know if this still works because I no longer own anything Roku and Netflix’s service hasn’t been worth that kind of shenanigans for a long time. It likely doesn’t work anymore.