I like the holster idea.
I’d forgotten that in high school, my best friend had a three-pocket waist apron from working at home depot or something, and we started wearing those all the time. We talked about sewing them in all sorts of styles and starting a business but then moved on to other projects and forgot all about it.
I have a garter pocket that I used on my wedding day for my vows, but it was pretty awkward (and the pocket is pretty small).
You say we have complete choice, but to me, the issue is so much bigger than one person’s choice. Yes, I’m in control of the personal choices I make, but that won’t fix the overarching cultural problem. And I’m painfully aware of all the ways the cultural clothing norms for children affect how the kids think of themselves and what they’re capable of.