Want to water to kill the bugs before bringing inside. Read where some use hydrogen peroxide and others ammonia. What is the best to use?

I use Insecticidal Soap. I water my plants with it and also spray the foliage a couple times before I bring them in.

what ratio do you use to water?

Same as for mixing spray. I think its 1/3 cup per gallon of water.

I have never found dosing the soil with peroxide or insecticidal soap to be an effective way to treat soil-born insects. Concentrated ammonia will probably kill the plant.

If you leave a plant sitting in a tub of water for a couple of hours, that may drive the insects from the soil as they search for oxygen. But that only works on certain insects.

If insects are a problem for your house plants, you might want to reconsider moving them outside in the warmer months.

I think Will is right. I used to move plants outdoors but it was such a hard job that they now stay indoors all summer and do just fine. When I used to move them in and out, I'd re-pot with fresh soil before bringing them in. Just spraying and such didn't get all the insects out.

What bugs do these plants have?