Wow, that sounds like a ton of work. I think a better idea is to use an ad-blocker, but run a program in the background that downloads the ads (or maybe just samples them, to save bandwidth and resources), processes them to find brand names, and then stores these brand names in a database so you can find their relative frequency and assign a score to each. Then you can just query the db when you want to buy something to find that brand's acceptability score.