Could you at least pretend like you care about doing good, which would be admirable though naïve?
You specifically asked "would it look good on a residency application." Having been born in a developing African nation and working for field-operations like MSF, we all not-so-secretly hate your guts.
1. Don't be a voluntourist.
2. Don't practice or be put into a position where you might practice medicine above your competency (which as a MS2 will be exactly diddly.)
3. A lot of these programs are frankly exploitative. They often do more harm than good.
4. Why not save the money from this trip and buy some mosquito nets? That would literally save waaaaaaaaaaaaaaaay more lives than you'll ever likely save in your entire career as a doctor.
5. Why not do something to help all the poor people in the US? They need your help too. You already know the language, the resources, the culture, and some would argue the lower Mississippi Delta or parts of the Appalachian are almost as under-resourced as some developing nations.
Edit: Guess what? I Googled "Projects Abroad." Here's its pitch, "Voluntourism allows you to engage in tourism while doing meaningful work as a volunteer." Frankly not impressive on any residency application.