Go with the bracelet, pretty easy to find, and you can even make him wear different charms on it!!
Why not a chastity device or cock harness?
Bunny12

Bunny Rabbits cute and fuzzy they want to love you but they have razor sharp teeth - don't piss them off! He already wears one,but I want a more public means of humiliation
, and marking of my property..
I was thinking of a silver chain with a big bubble shaped heart charm on it.
"When its too kinky for everybody else, its just gettin' good for me."
(Kinky Freedman)
How about a fannypack? I can't think of a more emasculating adornment than a fannypack. He can store his balls in it.
Design a tattoo for him. Something symbolic in a discreet location.
Dancing Doll: GREAT idea, I'll have to work on it. Any ideas?
"When its too kinky for everybody else, its just gettin' good for me."
(Kinky Freedman)