As I noted in my first post in this thread, I have not heard of making basil into a spray to repel insects from other plants.
I was just remembering when a colony of ants decided to take up residence in one of my potted basil plants! They didn't seem to have any objections to the environment, and I'm sure they would have brought their little freeloading aphid friends along had I not issued a stern eviction notice.
I am having the same any problem. What did you use?
I submerged the entire pot in water for 20 minutes. After I removed it from the water, I put a bubbler on the garden hose and let water run into the pot overnight, so the soil was thoroughly drenched. The ants moved out sometime during the night. The plant did fine. Overwatering a plant once won't harm the roots, as long as the soil is allowed to drain well afterward. It's repeated overwatering that kills roots.