I believe you can delete your own notes easily but any reply you make kinda gets tied to the other person allowing you to "request deletion" (on amethyst at least). No idea how reliable this is though.

That being said, it's not like anything online is really deleted as soon as the user deletes it, so I don't think it's a huge difference in actual security.

Been using them for a handful of years now and haven't had any issues or regrets 👌

Looks pretty well documented so shouldn't be too bad for those willing to do a little work. 👌