I don't know the economics of it, but they could run ads on their site, become a non profit & only accept donations, etc etc.

This is slightly unrelated, but I remember in the 2000s, there was a vendor of protein powders who started testing his and other vendors protein powders to see if their labels were true & they weren't protein spiking (adding cheaper collagen instead of whey lying on the labels, essentially). He almost immediately got sued from several large mfgs and had to shut down.

So, for this group, and the fact that they're ignoring cease & desist letters from the toothpaste mfgs they're testing puts them in HUGE legal risk, I suspect, and would not be the least bit surprised if all the funds they're collecting are going to end up in lawyers pockets.