I had a time with mud daubers when we kept our boat in a slip. The dryer sheets worked but they don't last long. I kept a box in the cabin easy to get to. You have to put them everywhere that looks inviting to the daubers. I even stuck them in thru hulls when we left the boat, sail covers, bimini covers, everywhere. The flip side of this is that when I got rid of the daubers, the spiders took over.