Search "Nuke Reddit History" for a browser extension that will do the magic. I'm running it now and it's working well. Very satisfying.
People may come across your old comments via search engine or otherwise. May as well give them a shitty experience when they see some comments deleted.
It's deleting all of my comments from most recent to oldest. One of the comments for the app suggested you can't be in their newer reddit design. Not sure.
I purged my account back in 2017, and I recall having to use a couple of products. I had to install Scriptmonkey in Chrome and run a script that overwrote all my posts (seven years worth) with gibberish, because posts can be undeleted intact. Then I ran a separate tool that deleted all the posts, the deleted my account. It took about four hours.
^^^^ This dude deletes!! ^^^^
I wanted to make sure absolutely all of it was gone. I had contributed short stories, how to's, and a whole lot of material to /r/reloading. I wanted to make sure they could never use any of it. It was around the time that stonetear was revealed. I had been ranting about Hilldog's private email server ever since it was first exposed, and everyone, including everyone in my family, thought I had lost my mind. The problem is I knew what I was taking about, having run Groupwise and Exchange email systems along with Blackberry Enterprise Server to tie in mobile devices securely, some for lower level State gov't agencies. I knew what she did was wrong, and I knew the president had to know because he was exchanging emails with her. When the stonetear messages broke , I couldn't take the shilling anymore. I created my account here during the Ellen Pao shitshow, but that last burning dumpster fire did it for me and I moved permanently.