Do moth really act as a snake deterrent, and how do you use them?

I am terrified of snakes, and we have a little man-made pond right up against our house. Needless to say, the snakes live under our deck and sun themselves by our pond. We've tried the store-bought snake deterrents. Our house stunk like garlic as the snakes continued to sun themselves. I've heard moth do the trick. At what rate do you spread them and do you have to re-spread them after rain? I'm desperate. I despise snakes, even those "harmless" garters! What really works!!