gaps on plugs shuld be 40 thousands run cold plugs to reduce detnation

 

I think I fouled my colder plugs. I pulled them out after running on a 9:1 AFR and they were black as night. I tried sanding them down and installed them but it sounded like it was missing. I put the stock ones back and it didnt miss, no detonation either. Is there any way to clean them better?