I use my 9x9 "Capture Go" and 5x5/7x7 "Stone Counting" teaching board to teach others about go. You can print them out for free.
Did not really understand or seem interested in rules. Played "put the pieces on the intersections" instead. Occasionally showed a capture. Session lasted 5-10 minutes.
Age 6-7 - Korean-speaking student, English-speaking teacher:
Wanted to play "Stone-capturing" method, but it didn't infuse excitement. Plus the language barrier was too great to explain any subtleties.
We ended up playing capture go with an animated "CAPTURE!" from the teacher, eliciting smiles and laughter each time from the student. We played 2-3 games. The session lasted maybe 15-20 minutes. The student seemed to really understand the basic rules of the game.
Age 30-40, experienced gamers:
Over lunch, showed the 9x9 board started with a brief introduction "These are all the rules" and played a series of problems "where to capture, where to avoid capture". We then played capture go 2-3 times. (Before the game I usually start with handicap of 5 and play on the side star point (on a 9x9, that's on the 3-line). Student (as is usual) starts by placing an attached stone at the 2-line. When I attach, they rarely extend, that's when they lose, and then I show them the sequence slowly and note that they lost by 1) playing away from all their stones losing the ability to connect and, 2) not extending, starving the stone of liberties and a chance to survive. Usually by the fourth game, we're playing beyond the first capture and then I get a chance to show scoring. For most people, 4-6 games is enough to see the subtlety of the game and pique interest.
Then showed the "stone counting" method and we played on a 7x7 board. I captured the student's stones by placing a stone in one remaining eye. Then I explained two eyes and life & death. "Wow" was the response "I can see how this can get interesting". The session lasted 10-15 minutes during lunch and between bites.
We also talked about the balance required and the "yin and yang" aspect of give and take, a brief comparison to chess (battle vs. war, singular focus vs. whole board territory). Overall, the session was very well received by the three people at the table.
I no longer use "complex" in my description of Go. I'm influenced by Paul Smith's 2008 analysis "The Image of Baduk in the West: Marketing Baduk to the public in the United Kingdom" wherein he writes: "All this seems to add up to an image of Baduk as a game which is difficult, takes a lot of time and effort, and is perhaps somewhat elitist and only for very clever people. Perhaps the game is not often seen as providing a lot of fun or enjoyment."
I hope this helps in your teaching, too.