I do believe however that it is possible to have an influence on what people experience. For one it is not even necessary to travel to remote villages. One can see the reality in the cities and just a few km out. I would introduce them to average people here, meet business owners and give them an insight to what is a typical life here.
This also should not be a short trip. A month minimum. And ideally not in a hotel but some form of homestay or maybe AirBnB where you have to cook for yourself. Go to the market, buy ingredients, realize what is available to the average person. Then maybe visit a village and find the difference. The idea is to get an experience of what is it like to live here, and not just be a tourist.
Any of these visitors can then multiply their impact just like you did. They can motivate their friends to sponsor students and act as ambassadors.
I'm curious if you think a documentary could have a similar effect. I'm an amateur filmmaker by hobby and I've been thinking of filming a "Cinema Vérité" type documentary showing the humanity of Tanzania and trying to relate it to life in the US. I think it could be powerful but difficult to get right. I'd love to hear what you think about that.
A documentary can't have anywhere near that effect, it could however motivate more people to investigate and maybe get some people to travel. It also would support the legitimacy of your project. Since if already fits with the things that you like to do, I'd say, go do it. As I wrote in another comment, we should try to find a way to contribute that is most suitable for each of us. And we should make use of all the skills available to us to further our goals. If documentary making is in your set of skills and interests, then by all means.
If there are people who want to do that, maybe I can help arrange things locally. I would recommend individuals only, or families, but not groups in order to allow the visitors to focus on their interactions with locals and not just socialize with each other.