Seconded. On the orange site you can un vote something. That might not be part of the public version of ARC that runs these kinds of sites. The only upvotes I regret are the misguided or spam posts that I upvote by accident. Alas, this feature may not be in the power of our benevolent host.

I try to give everything I see in “new” an upvote so so that it makes the front page. From there the decay function can be applied to the post to determine if it’s not interesting.