Engineering barriers like that has been ineffective to me because I like to dismantle them, like that Frog & Toad story where they keep escalating their strategies to prevent themselves from eating all the cookies until they have to give up, realize they'll never defeat their own ids, and give the cookies to the birds. The lesson here is that the only way to break the habit is to physically destroy reddit's servers.

Failing that, I've found it effective to do a shorter challenge, like a month of no reddit. Once you break the daily cycle you can see that you weren't really missing anything and it becomes easier to just replace the habit in question with something else.