I put down a lot of bricks and stones last year and I'm getting a lot
of weeds in the cracks. Much of this is away from desirable plant life
so I don't need a specific solution.

I've heard vinegar and a preen follow up. I know nothing about Preen
and I suspect it's the acidity that works in the Vinegar.

I've also vaguely heard about some kind of sand that keeps the weeds out.

Suggestions? I've been hand weeding, but it's an unfair contest.

Jeff