There are barrels outside the lighthouse and recycling center.
Chat with our AI personalities
You click on the barrel next to the barrel that said cream soda
you shake it... i think
Go into the Lighthouse and go over to the penguin pushing the barrels, ask him for one, and put it in your inventory (If you can't get one, try clicking a barrel). DO NOT SHAKE IT YET!
Not on the current Club Penguin but I think that they have old Club Penguin on Penguin Chat.
Rockhopper.