That website describes that.
TLDR Spoofed characters look like normal characters but they're not and, unless automod has a filter for them too, it won't detect them.
I wonder if the next move would be to ban posts that invite people to move to reddit alternatives. Elon Musk did that with twitter, I wouldn't be surprised if Steve Huffman tried to do the same. Maybe communities should use this time to organize on where to move while they still can have those kind of discussions.
The support page literally says that you have to delete everything manually. Their privacy policy has a bit more details and from what I can understand you can send them an email to request data deletion, but I'm not sure if they'd have to comply unless you're a EU or California user.
Depending on where you live, you may also have the right to request access to or ability to port, deletion/erasure of, or correction/rectification of, your personal information [...]
I'm not sure if I had more than 1000 comments, but I did manually delete everything that Power Delete Suite didn't catch. My account was completely empty except for a few comments that I posted after.
I think this needs more visibility though, maybe a sticky or something. If people delete their accounts after they think they've deleted everything, there's no way to go back and delete the stuff that reappears. Maybe if you're in the EU you can ask reddit to delete your old posts and comments but I'm not sure.
Are you 100% sure? Have you verified (with e.g. a screenshot including the permalink in the URL bar) that the comment/post was deleted previous, and it's showing up again?
I definitely am. No hidden posts and comments, all deleted. I did it I think three days ago. Now I deleted everything again, let's see what happens.
Power Delete Suite and manual deletion.