I’m sure other people will find this thread as I did.
The actual place to hide this block is:
Appearance > Pagelines Settings
Template Setup > Select Template Area > Morefoot Area
Below “Displayed Morefoot Area Sections” you should see Twitterbar.
You can now drag it over to the Available/Disabled column, which autosaves. Or you can leave it active and hide it, see Advanced Setup, which you expand, and click the two checkboxes to hide it everywhere.
https://www.dropbox.com/s/qtygtmsdc6e8md5/Screenshot%202013-12-04%2013.58.57.JPG
Then you’ll need to click the blue save button way down at the bottom right.