Termidor SC is labeled for against structures 1 ft and 1 ft out. It is safe if it had at least 24 hrs after application to dry prior to rain. We do offer products that are great for other areas on the structure for carpenter bees. Please take a few moments to review our treatment article on How to Get Rid of Carpenter Bees and our Carpenter Bee Control Kit.
Yes, Termidor SC is labeled for centipedes. Keep in mind that this product is labeled for outdoor use only. You will apply at a rate of 0.8 oz per gallon of water, 1 foot up and 1 foot out around the perimeter of the structure you are treating.
Termidor SC is not labeled to be used inside except for spot treating active infestations. If applied as a crack and crevice spray inside cabinets it would be recommended to thoroughly clean the area with warm soap and water or an all-purpose surface cleaner.
If your crawlspace is sealed then no you would not be able to dig a trench and apply Termidor inside the crawlspace, you would only apply it around the outside perimeter of your home.
It would be a great benefit to add a barrier spray outside using Termidor SC.
Just about any 1 gallon pump sprayer will do. We prefer the Chapin Premier 1 Gallon Pump Sprayer 21210XP because of the brass construction in the shutoff valve, wand, and nozzle. The nozzle is adjustable and using the pin stream spray would allow you to spray through a hole in the wall. All of the parts are replaceable when they wear out and when cared for properly will last for many years. You may want to look over our How To Do A Termite Treatment article to learn how you can protect the rest of your home against termites in the future.