Well then, disregarding all other criteria, I would say partner swapping...
I have 2x shampoo and 1x shower gel. Child 1x something. I can no longer count my wife's bottles during a shower.
Haha, clichés that apparently often have a real reason after all.
I remember back when in a past life a "typical" 1-liter men's shampoo bottle was called annoying, while the 17 different bottles and tubes I counted myself were called decorative but above all indispensable. In the new life I always had my own bathroom and so it will be again, I like that.
on the man's shelf: 3x shower gel, of which 1 empty and 2 opened, 2x half-full shampoo (same kind), 1x shaving gel, 1x razor plus changing bottle clutter.
tsk tsk tsk... totally unmanly, tell him that and give him a usual liter bottle for Christmas. On the other hand, one might also conclude from this that he feels compelled to do absolutely everything so that you can enjoy his appearance. Lucky you.....