Google used to let you blacklist websites many moons ago, that would go a long way already.
Now there are a few extensions that do that, but obviously they only hide the results from each page, so sometimes you will see pages with 2 results, if any at all.
Now there are a few extensions that do that, but obviously they only hide the results from each page, so sometimes you will see pages with 2 results, if any at all.