@Brad771 Only Mexican residents can get an RFC number. You can't get one if you come to Mexico on a tourist visa. It would be like a tourist in Canada getting a SIN- not possible.
You really need to find a Mexican accountant familiar with Airbnb accounting to deal with this for you.
@Brad771 Well, your post title asked how to get an RFC number and as a non-resident, you can't, so I'm confused about you saying you are aware of the rules.
If you do have residency, you can get an RFC online.