Unlike cosmetics, additional steps need to be taken in order to successfully remove a pose. You need to keep an eye on 2 files:
XComContent.ini
XComGame.int

Both the pose entry in the XComContent.ini file, and it's name (localization) on the XComGame.int file, must be commented out (add a semicolon in front of the line) in order for it to work.

If you only comment out the pose entry and not it's name, the names will re-align in the wrong order, having names/poses not match.

Follow the image posted in the main workshop page.