I had monti black bugs, which I guess are similar to redbugs, and decided to use Interceptor because I wanted to continue trading/selling and nobody knew if they were bad or not. I followed the commonly prescribed dosage - about 1/3 of a large tablet for my 120G system. Of course, I took all the snails and hermits out that I could find first. I treated for 12 hours before doing a 25G water change w/new carbon and GFO.
Within the first 2 hours, all black bugs were dead. My cleaner shrimp that I couldn't get out made it through just fine, as well as all my pistol shrimp, snails that I didn't get, emerald crabs, gorilla crabs

, and most porcelains. I probably lost about 15 hermits that were still in and about 3 porcelain crabs. Other than that, I saw nothing but positive effects. Heck, I may have even killed off some parasites living in the fish. I was very happy to see some good pods still running around the refugium too.
One important note is to wait to put back in the hermits for at least a week. I lost about 5 of the ones I put back in 24 hours after the treatment. But now the rest are fine. I ordered more snails and hermits to bolster the numbers after the treatment, and some good pods too. Other than a turf algae problem, my tank is doing well.