You may find a pocket here and there, perhaps in a new development with properly paper-flushable toilets, but the vast majority of homes and businesses provide a bin for used TP. You could always include a bidet toilet seat among your "must bring" items: they can cost anywhere from $25 to several hundred dollars on Amazon. If you can't stomach the idea, you should probably not consider living here. Or maybe try the Middle East or Asia, where in many public loos you are provided with a hole over which to squat, and a jug of water with which to clean up, LOL!
A few topics back toilets were covered in detail along with a link to the real scoop on paper or not down the toilet. My town in Sonora state has a public sewer system so flushing paper is no problem. Little old houses and businesses are probably still on a separate tank and probably little or no drain field. Dispose of paper in the provided container there. If you have great issues with the toilet paper then maybe Mexico or other developing nations are not for you. Many folks living in the US off grid deal with this issue also. I have friends in C. California with a cesspool that have the honor of burning the used toilet paper on a regular basis. Some folks with cabins in the mountains use an outhouse and either move it occasionally or put lye down it regularly. Every society deals with it one way or the other.
I have stayed in hotels inwhich this was not and issue at all. I went to a restaurant in an old building in which it applied. Even when it was the case, it is not this horrible thing that you are making it out to be. New homes there have modern plumbing and water filtration systems.. if you go out to some small rural market, you need your own toilet paper. But none of it is as awful And distressing as you seem to have concluded.
If you it all bothers you that much don’t go!! It is a foreign country with differences. Some who don’t like it complain it is noisy as well. I didn’t find any of it so objectionable. I enjoyed the experience of a different culture.
Toilet seats go missing from commercial locations in Latin America (and probably other places in the world where there is poverty) because people steal them. That said, last night I ate at a local Italian restaurant and discovered they had a padded toilet seat in the ladies' room!
This is not a problem unless you go to a rural area. I am almost 59 years old and was born in Mexico. We always put the paper in the toilet, even when we lived in an old house were my great grandmother used to live. I left Mazatlan to go to the university in the US and did not come back until I retired last year. I think a lot of people who move to the city from a rural area think they can’t put the paper in the toilet and continue to put it in the wastebasket..
I personally don't know the rules in many hotels I go to in Mexico so I look at the waste basket. If it looks like it's important or opens with a foot pedal, I assume you're suppose to use it for used toilet paper. I also just assume it in every building older than 30 years throughout Central America.
I can't help but think that those who have never been to Mexico and occasionally post about wanting to relocate to Mexico for retirement might come down the first day and have their first rude awakening! heh heh
In reality, you get used to it. But the thing that troubles me is all those hotels who are routinely disposing all those plastic bags holding the used toilet paper is a real environmental waste. Which is a serious matter.
It IS a general rule to not flush paper down the toilet. I live in the capitol city of the Yucatan, it is a large and sophisticated city. Most restaurants you cannot and most housing you cannot, new or old. Unless they are ripping out the old pipe system, new house doesn't equate to new flush.
One reason you may see the small trash can in restroom with septic systems that can accept paper is many Latins will not equate 'no trash can' to 'you can flush paper' and will just throw the used paper on the floor. This I know from personal experience even when you tell them they can flush paper.