The alternatives were mentioned in the episode, but they aren't on this website. This was from the last section, which was something along the lines of "if you absolutely need to use their products, you can still have some impact. Here is a memorable website you can link people to"
The permadelete_for_creator function (called by the purge_user_account function, which is called by the delete_user_account handler when delete content is true) updates every comment of the user to contain the predefined text "Permanently Deleted".