If you use Shreddit (or similar) check after a week that things are really gone!

Shreddit is a popular tool for deleting comments on Reddit as a means of protest. However, I noticed that after a week or so there were a dozen or more comments from 9 months to a couple years that showed up again. No idea if this is intentional on the part of Reddit or not, but if you want your comment history gone, double check.