Problems with the prefix aside (I'm not a fan either) Reddit does it's best to show you popular comments. If you go looking in the -10 through 10 range on relevant threads you'll have a decent chance of spotting them. Not "controversial", not "top" (or bottom of "top"), not "hot", just the 95% of comments that aren't driving engagement numbers.

After all it's neither going to be popular because it's a popular sentiment nor is it particularly likely to be something interesting/relevant to get upvotes on merit. It's just going to be an unpopular opinion that gets ignored.