Why bother? You just end up with "crud catchers" that take extra time to clean out.
The beauty of porcelain is that you can use a blower to keep the floor clean most of the time because very little sticks to it. If you live up north and drop "poop-cicles" off your car every time you park in the winter, just hose it out and use a nice big squeegee to push the water -and dirt out. It leaves the floor spanking clean.
Now, if you live up north and you are worried about freezing your door closed due to melt-off, I'd look at silicone spray or some other non-stick on your door edge. My worry with metal inlay channels is the expansion on metal is very different than tile. Eventually, it will break loose. Then you'll end up gluing it back in every year. Unless you have a drain inside the garage to run it to, what have you gained?