Eh, it's fine to cook with. Just don't let it sit in there and oil your pan when you're done!
Fun fact: Soap is absolutely the way to clean your cast iron. The old advice of "soap will ruin your seasoning" is based on old soaps which includes lye, a strong base. Modern dish soaps are very gentle and are perfect for cast iron! Note that this doesn't include dishwasher detergents, those are very aggressive and will ruin your seasoning.
Liftoff isn't too bad but it's just not the same polished experience that Sync is. Plus it handles messaging weird imo