Don't give up. Last year, my husband orange oiled ours every day and he won the war. This year, we are watching diligently for the adults (including any kind of leaf-footed bug), killing the nymphs when we find them, and smooshing the eggs when we see them.
My suggestion would be to skip the Garrett Juice and just use 2 oz. orange oil per gallon of water and do it every day. Also, get out early and look at the base of the plants. The squash bugs aren't out once it gets hot. The nymphs my husband squished this morning (about 20 of them) took their last munch of our squash plants around 6:30a.
Again, don't give up! You can win!
One last thought, though, you said "your plants". I assumed you meant squash plants, but what are they destroying? It's possible they're attacking plants that are under stress...