One of the problems you will have is finding a dive operation that will allow you to do the instruction. It is not as easy as you might think.
A while ago I certified two friends, and after scouting out how to do that, I chose Akumal in Mexico. The reef is close to shore, so everything is done in one-tank dives. Most of the sites hafe diving within OW class limits. You have access to nearby cenotes for dive options as well. I called several operators, and only one would allow me to do the instruction. The others said their insurance would not allow it. Fortunately, the one I could use was right on the beach at Akumal Bay, and we were staying right there as well. On one of the dives, my students and I were the only ones signed up, so they did not send a DM--they just had me control the dive. It was all cheap and easy.
I once led a group trip to Cozumel, and I was also allowed to do my own instructing for a couple of the people. That was normally not an issue, but on one occasion I had to take a dedicated boat trip for OW dives (Which are, of course, shallower than typical Cozumel dives), and they said i had to have one of their instructors along, and we were charged extra for that.