At one of the street projects, a Glitch uncorked a Rainbow Juice under the vendor. It was amusing at first, until I realized that I could not get close enough to the vendor to participate in the street project. People were expressing frustration in chat because we had lost control of our characters. I fear Rainbow Juice has griefing potential, keeping players away from poisoned trees or making it difficult to reach vendors, signs, or building entrances. Rather than change Rainbow Juice because it's good fun if you're in the mood, I'd suggest a new elixir.
Gravity Serum: Increases your weight, keeping you from being affected by Rainbow Juice or Spinach. Has the curious side effect of making you unable to triple-jump.