I have some YUM garlic, but I don't use it anymore since it dyes the lure a green color, and I had spilled some in my last bag and dyed half the bag green, not to mention the stink that surrounded the bag within a ten foot radius. I buy lures because I think the colors will work for certain conditions, not so I can spray them with green dye.
Anyway, you can get away with using it every 20-30 casts or so. It is like an oil and it tends to stay on the lure for a good bit of time.
You can use attractant on anything you throw in the water if you want to. It's up to you.
I only use attractants when the bass have lockjaw and don't seem to want anything.