That's a neat recipe!
I don't know much about outdoor ant control but I do adore one solution for indoors that's perfectly natural. We don't seem to have any problem with ants so I leave them alone.
Mycologist Paul Stamets created a way to get rid of indoor ants and termites with a type of fungus. He inoculates plain rice with the fungus and sets it out on plates for the ants to consume. The fungus colonizes their little bodies, makes them a bit crazy and eventually a tiny mushroom grows out of their heads. And the remaining fungus carried away to the nests makes any new ants or termites to not want to set up house there.
Very cool.
http://blog.ted.com/2008/05/paul_stamets.php