It works great. I do it all the time
The idea is to do it once and then not have to. I believe you proved my point.
You may kill many of the workers, but the queen is safe and sound well underground.
I have dug up ant nests, poured kerosene in the hole, set ablaze. They are back in full swing next year.
I have placed a Terro bait outside the nest and had no ants since. Repeated for all colonies within 50 feet of my home. I spray my foundation line with their blocker, and have not seen an ant in my house in years.