I bought your beautiful texture molds. I fired them a few times with good results. Now it is time to reapply kiln wash. When I fired last, the wash came off on my glass. How do I get what is left of the kiln wash off of my mold? I have been scraping for days. Due to the textured nature of the butterfly, holly and dragonfly molds I cant use my regular sander. Any suggestions? I have been using a thin "scalpel" like tool to scrape into the grooves. It is very tedious. I even soaked them in water for a few days, but that barely removed anything. Would appreciate any suggestions. Thanks