We were on the second or third raft over in July and the CM told us about the paintbrushes. He just said you could turn them in for a "surprise", and that you should just take one per family. We had never heard of this before! Of course there was a family that didn't listen and had gone around and scooped up as many as they could find. We searched and searched and couldn't find a paintbrush. The other family finally tried to turn theirs in (they knew they would get fastpasses and wanted lots of them) they found they would indeed just get one for the whole family. They kindly went back and found us and gave my son one. It was our last day, so we saved our certificate to ride Splash Mountain as our last ride of the trip. It was great because the standby line at that time was 110 minutes! They did seem to know what our certificate was and collected it at the same place they collect the other fastpasses. We had a great time on the island and the hunt for the brush made it even more fun.