I know there are a variety of methods to remove the nasty weed stickers we get in the field.  Especially tough are those on fleece clothing.  I've tried a lot of ways but I always seem to come back to this little gadget.  It was designed to remove flees from pets but it works pretty slick for me.

I've always used a butter knife, but your gizmo shows promise!

I got a neat little thing called a Burz Off or some such from G. Fred at Compton's last year.  Works like a charm and didn't cost much at all.

I got tired of removing the goathead sticker that plague this area so I just switched to snake boots and previously snake chaps.

I have always been a "butter knife" guy... LOL