Stay logged out of Google account(s), clear your cookies, and go to the channels you already like to (re)build your 'preference profile' associated with the new

Stay logged out of Google account(s), clear your cookies, and go to the channels you already like to (re)build your 'preference profile' associated with the new cookie that Google sends you. Perhaps use browser profiles to separate your logged-in and logged-out 'personas'. If you want to watch a video, but don't want it to contaminate your current preferences, watch it in a private browser window.