I have done very little casting over the past year and a half so when my supply of Lee 125RF's ran out I went out to cast some. Mold has been on a bench in the garage the whole time. Opened the spru plate to find all 6 cavities full of mud dauber cocoons! Soaked overnight in Dawn and water and that got a lot out. Those things are really tenacious. Whatever the excretion is nothing seems to cut it. Used alcohol,carb cleaner and finally Barkeepers friend with an old tooth brush. Next up a bunch of tooth picks for the edges and grooves. Tried casting. Still some fill problems like the mold is cold but it's not. Sprayed some carb cleaner in the hot mold and things improved but still some minor fill problems. Dauber spit seems to be acting like oil in the mold. At this point I'll just run the mold hot and see if things clear up. Sure wont be leaving the molds on the bench in the future!