Yandex Ads network has a wonderful button - "I'm already bought this product" to stop ad spam on the things already at home )
That clicks all adds for you. Maybe it can be modified somehow to click already bought item?
* Big businesses are unaffected as they use click fraud prevention services.
* Businesses that don’t use that have to pay more money to Google because people clicked on their ad, and they think their marketing is effective (at least from a click through perspective).
* Google makes even more money because you are clicking on all the ads and it makes them look better. They can demonstrate how well their marketing platform works even better!