Here is a goal: how to remove weeds in patio cracks

Which way makes more sense to accomplish this goal?

Choose from:
a). Generously pour boiling water in all of the cracks in your patio. You may need to repeat this method 2 or 3 times to see significant results.
b). Generously pour boiling water mixed with oil in all of the cracks in your patio. You may need to repeat this method 2 or 3 times to see significant results.
a).