I would consider something like that but I don’t know anything about the legalities, or even if there are any legal/tax issues. It might be that in order to do that it would require a 501(c)(3).
Legal part is easy - advertising.
T-shirts, banners etc may have sponsoring company name with whatever they want to say on them - expenses written off as advertising, no need for tax exemption.
On top of that you can always find a non-profit or smth to donate to " a green cause"