You know, that is totally what I heard over and over from my Ceramic's Professor, don't fool with things, just do another. That being because he knew how easy it was to throw a hundred cups and he knew I was capable. I totally agree with his advise, yet, in my home studio I use paper clay or mix sodium silicate with a small amount of ball clay. (I use sodium silicate to re-attach bisque parts) In this case, it fills the gap, I glaze fire it and found that it has been successful. I stilt it for safety if it does melt through, never has. But my feeling is, it's all an experiment each time the kiln fires up. Learning by mistake only comes by trying. Good luck, try, that's the advise I prefer. It's been successful for me.