Well of course you’re finding dead roaches… that’s what the Ortho Max is for.
But it’s not some kind of force field. As a home ages, cracks in walls, baseboards, around door frames and the foundation all conspire to allow roaches and any other kind of small vermin in to your home.
Finding and sealing all of those holes and cracks wouldn’t just help keep out the bugs, but would also would likely reduce your utility bill as well, since you’d be losing less heat/cold to the outside. But it can be very expensive.
Stop gap measures like filling any cracks you find with something like silicone or spackle can help… assuming you can find the most traveled routes.
If you really want a “force field”, then try also applying the Ortho Max outside around the perimeter of your home, per the instructions on the label. Maybe then you’ll kill the bugs before they get a chance to step inside.