When this topic was trending before, many months ago, I proposed the idea of a locking “chastity bracelet”.
This could be a simple band of solid metal, of the type manufactured by Axsmar and SM Factory:
https://www.axsmar.eu/Stainless-Steel/Hephaistos/Hephaistos-bracelet-15x4::22.html
https://sm-factory.com/products/heavens-hell-2er-set-armbander
The bracelet would be engraved with the words “CHASTITY”, or “TRUE LOVE WAITS”.
The son or daughter would wear the bracelet, and the parents would hold the key.
These could be marketed to the “Purity Balls” people, to kinksters, and to members of our community, the “serious use” chastity belt community.
The bracelet could also take the form of a miniature chastity belt worn upside down on the wearer’s wrist (If you prefer to wear yours right side up, that’s fine with me.) There could be one piece of metal shaped like a letter “O”, and another piece shaped like a letter “U”. The two pieces would be held together with screws, or with a hinge and an Axsmar “click” lock.
I suppose it would be problematic to put a non-adjustable bracelet of this type on a wrist that’s not yet fully grown.