Give manager cookies that have baking soda all over them, tell them it's sugar. When they eat it, their mouth will dry out and they will drink anything. Offer them a water bottle, though it's actually vinegar. Enjoy.
Dress up as the adoring fan from Oblivion, walk up to people and say "By Azura, by Azura, by Azura, it's the Grand Champion! I can't believe it's you! Standing here, next to me!" and then proceed to follow them randomly exclaiming adoring fan quotes.