Power Delete Suite
Generally works, but I think it can’t see your entire Reddit history. After deleting a few hundred comments and posts, it stops deleting.
Yeah, I can't speak for other tools, but I used PDS for almost as long as it's existed. PDS could only ever see the last 1000 posts and 1000 comments that you've made in your account history, so that's all it could delete. Apparently it was a long-standing limitation on reddit's end. So best practice was always to run it every couple months depending on your activity. But when the API fiasco happened a lot of people flocked to these tools without knowing about the limitation. Which understandably caused a lot of confusion when people googled their username and found a bunch of comments and posts that PDS or other tools were unable to find.
Edit: I'm speaking from memory, based on what j0be, the guy who wrote the script, had said years ago. So my numbers might be off, but there was a limit to what PDS could access. Sorry I couldn't answer your question OP, but figured I could at least confirm your suspicion.