If that does not work you can step up to Bayer Temprid. It even kills bedbugs. Residual lasts for 6 months.
Now, treating the bites? I've been bitten by Brown Recluse spiders 2 times. Simplest treatment is cut down a nitro patch the size of the bite area and leave it for a couple of days. It will dilate the blood vessels and allow the body to clean up the venom. Everyone who tried this has succeeded in clearing up the bite.
I have even used 1/4 of a nitro tablet on top of bite, one drop of water to dissolve, covered with band-aid for a couple of days. Always works.
There was a doctor in Ft. Worth that regularly treated his patients with this.
Nitro patch?