Why not just clean the soil from the infested pots and maybe replace it with new soil not infested with ants?
Lambda-Cyhalothrin is a pyrethroid, a synthetic pyrethrin product. Depending on the dilution the manufacturer made the label will have something printed on it ranging from "Caution" to "Danger".

Here is a link that might be useful: About Lambda-Cyhalothrin

I have found a wonderful answer to this problem. I was advised to use dried molasses all over my yard and gardens. It is very beneficial. I can't remember what it does, but my entire garden perked up after I just threw it around. I guess you could google it.
A side bonus is that all the ants leave. I have no ants anymore. I don't know of anything else that gets rid of them. Also the jury is still out, but I think we have also gotten ride of all the snails and slugs. Hope this helps, Carol