Everest lost its misting due to poor design; it was water based and interfered with track sensors. Instead of finding an alternative it was just removed. Spaceship Earths steam effects are generated from a single point; no steam in Rome means no steam for the printing machine. Tower of Terror had several systems; the boiler room again was water based and made the walkways allegedly slippery. The 5th Dimension system created condensation on the glass. But again, no alternative was used. Rock n Rollercoaster in Paris found the water based system made evacuation walkways too slippery. So they installed different system. It is possible. None water based systems need more maintenance and attention. Not to mention restocking.