I've got uBlock origin, but it doesn't block anything on Pinterest. That brings up a good point... on Pinterest it is hard to tell what is and isn't an ad because the only differentiator is the text below that reads "promoted by...". Everything else looks like a normal pin, except usually the content doesn't make any sense with my feed so I think look to see who is posting garbage so I can unfollow them and usually it turns out to be an ad.