The boiling water will "top kill" the weeds. Perennial weeds will resprout, small annual weeds will be killed.

You need a weed torch. Good top kill, though perennial weeds will have to be burned off as they return. Heck of a lot faster and more convenient than boiling water.

I don't know of any non chemical method of weed control that will translocate down through the roots.

Here is a link that might be useful: {{gwi:1350956}}

what about pouring vinegar on them?

My mother used to pour boiling salt water on the weeds that grew in the cracks of the sidewalk on the side of our house. It worked, from what I remember, but wasn't a permanent cure.