That works, or iron out and a wire brush, or wipe it out and season it with the bit of surface rust there and it will go away on its own.

Now the best thing you can do though, is to use an orbital sander (or a large amount of manual elbow grease) to actually sand the casting smooth on the inside of the pan before you season it. The casting being rough actually really hinders the non sticking, even with several layers of a proper seasoning job. Sand the bottom to get rid of the roughness from the casting and it will end up being your favorite thing to cook in. It will stay cleaner and more non stick and easier to wash than any other cast iron pan you can buy that’s not under $120. The ones you can buy over $120? Go check one out. The inside bottom has been machined smooth to get rid of the roughness from casting.