We carry a pressure sprayer aboard, typically used to spray lawns/gardens. We use it to wash dishes, or to hose down Pino's deck.
While in Victoria I was cleaning it, and a dock neighbor asked what was in the bottle. "Water," I said.
He looked paranoid, and later I understood why. He said he used to have the 'greenest lawn in the neighborhood', and would spray liberally to keep that status, but now he thinks the exposure gave him Parkinson's Disease.
He was afraid for us, that it was a 'used' sprayer. We've only ever used water in it, bought it new years ago.