Sorry, I read the "waist" as wrists. But that still seems somewhat awkward... Why wouldn't you just... You know... Buy a belt? That's generally what people use to keep their jeans up. And by the way, Converse stores sell lots of laces for cheap prices. They often sell extra wide extra long laces as well. I have a pair for my chucks which I rarely use... Plain white just seems to work more easily.
I'm pretty sure he didn't ask for your opinion. I'm not sure where you would buy long laces but try looking for Doc Marten laces for the 12-hole boots, or something similiar. Long women's boots naturally would have long laces. Maybe try looking there. Good luck and I'm interested to see how this turns out. Don't forget to post a WAYWT if you like the look .