The other day I received a response from author and LA historian Richard Carradine to my inquiry about scattering ashes as Disneyland.
"Yes, many people over the years have been caught trying to scatter the ashes of a loved one at Disneyland. It's apparently happened so many times that the park has HEPA vacuums and a protocol for such incidents. Obviously there are cameras everywhere in the park and in every attraction, so as soon as someone starts to spread a foreign powder, they can shut down the attraction or area immediately and clean it up. Even if someone covertly deposits the remains in water like on a boat ride undetected, most water-systems are drained and cleaned nightly. One Cast Member told me that its a shame because ultimately that loved one ends up in the trash. As for spirit energy connected to this, there are two ghost stories linked to this idea of spreading ashes. The Haunted Mansion is said to be haunted by a little boy (seen most often in the unload area), who according to legend had his ashes scattered on the ride by his mother. This was presumably many years ago before they started watching out for such behavior. It is said that his ashes blended with fake dust throughout the attraction and went unnoticed. There is also a little boy that has been seen riding in the boats of the Pirates of the Caribbean ride for the same reason. Although two identical ghost stories connected to two different attractions is possible, some believe this story is true of one attraction, and that over the years it has been falsely attributed to the other attraction to explain the identical nature of the two "boys." Who knows. I hope that answers your question."
Be sure to check out Richard's new book The Park After Dark for many more deep cuts from haunted Disneyland.