You're using the wrong lube if it rains frequently where you live. If you use an appropriate (wet) lube, you can simply wipe the chain dry with a paper towel after each rainy ride and let it dry inside. Re-lube every week or two. A spray-on Teflon lube is likely too light and will be rinsed away, so you'd have to relube after each ride, and it may not have anything to coat the chain (like an oil film) that would protect it from oxidation.