Interesting question. I have just returned from a trip to Santa Cruz Island, where I stayed in a campground and day hiked for a few days, and then hiked to a distant area overnight. I then had two nights back at the campground. I left some food and clothing behind, because I had to pack all my water for the overnight.

I simply left my superfluous gear behind in the rodent proof container at my campsite, along with a note explaining my itinerary, and that the gear was not abandoned. I was just as concerned about a zealous ranger as a thieving camper. No problem whatever. On other occasions where I have cached items, I have done so discreetly, and have had no incidents at all.