The biggest way in which I encountered blocked users in my feed/chatter...I kept seeing comments from people I follow who were engaged in arguments with the people I was blocking. Arguing with the blocked person in comments, replying to posts submitted by the blocked person. Much like how on tumblr, when people, instead of replying to negative DMs privately, they responded publicly, and thus it got into my feed.
I'll keep an eye out on my feed/chatter to see if the changes you made fixed that issue. Hopefully it does. Thanks!