You can do that if you choose, but it is not as effective as drilling the slab inside the garage. This is because the garage is a separately poured slab, meaning the termites could come from deep underground and come up to the surface under the garage slab, and enter the wall where your door is going into the house untouched. You don't have to drill every wall in the garage, just the walls that are not exterior walls, where you have living space on the other side of the garage wall and apply Termidor. So it is a personal choice, but drilling the garage walls is the best way to protect all entry points.
Termidor SC is only labeled to be used indoors for an active termite infestation. This product can only be used outdoors around the perimeter of your home for ants. We would not recommend spraying indoors for any other reason.
Termidor SC is not labeled for use around poultry houses.
Termidor SC works as a perimeter treatment around the foundation only; it is not labeled for use indoors. You could use Termidor SC around the foundation and then use Talstar P for indoors, cracks and crevices, and eaves outside where the wasps may be. Be sure to make your application during the cooler times of the day when the wasps are less active.
Termidor SC is not labeled for use anywhere near grazing animals and would not be recommended.
Termidor SC is not labeled for root aphids. If you can let us know where you will be treating, we can recommend an alternative for you.