I know it's practically gospel in cast iron circles but the "never use soap" thing is more nuanced than it sounds. A drop of mild dish soap and a quick rinse won't destroy your seasoning if you dry the pan properly and hit it with oil after. What actually destroys seasoning is soaking, harsh detergents and leaving moisture in the pores. The old rule came from the lye-based soaps of the past which were genuinely caustic. Modern dish soap is much milder. I'm not saying soap every time, I'm saying don't panic if some soap touched your pan.