We bought this hook when we were finishing our bathroom well over a year ago. Since the recessed panel in the bathroom door is less than 1/2" thick, I tried to secure the hook using construction adhesive (as opposed to screws). This did not work at all, so the hook has just been sitting around for months. I finally attached it today using stove bolts.
In order to cover the bolts/nuts on the outside of the door, I then installed this cute ceramic "bath" sign, which was inspired in part by this water closet sign I had seen at Just Beachy.
One thing off of the "to do" list.