OK, I seasoned my cast iron pan in a bad way by layering my oil in too thick. After heating, I got a black, carbon finish that was too thick and is all crackled. Now, I've wiped it down and washed the bits of carbon off. Trouble is, it's almost impossible to get all of it off. If I run a napkin around my pan, I always get some black specs of carbon on it. Now, can anyone tell me if this is dangerous to ingest? Should I just scrape my pan down and try to season it all over again?