Using the Runaway Bike HOT TUB is the absolute best lubricant that you can buy for your bike chain. You will need to remove your chain to perform the treatment, however.
Never done that before? Fear not. It's not as hard as you may think... and it's a great project to start doing your own bike maintenance. Check out this YouTube video on how to do it.
Or... you may be lucky and actually have a "Master Link" or "Power Link" on your chain... in which case you don't even need any tools. Take a look: