You're very right not to use that imported stuff when you have access to better garlic!
Maybe this will help, it's a method I also use to store fresh ginger, also something that ends up in the garbage.
It's dead simple and when you look back to your white truffle oil thread, you will find some similarities...
To freez ginger I peel and grate a lot of it over a large plate. I now have nothing else than pulp and juice. Mix it a little and then put some of that in the lower part of a plastic bag. Fold the upper half of the plastic bag over to the bottom and lay down folded like that. Now gently tap on the ginger to spread the grated ginger all over only the lower half of the bag in a thin layer. Don't make it thicker than 3 mm. Lay the package like that in your freezer. Now you can simply break off what you need.
I would suggest to do the same with garlic. Peel and grate or process in a foodprocessor and make similar thin layers in folded plastic bags.
Also same method for making truffle butter; grate truffle, add softened butter, bag as above!
Here's some left-over frozen ginger (don't mind the onion). You'll use your frozen stuff to the very last bit without waste and most important; without loss of taste!