Rust flakes in my eggs, fixed it with a potato

Last Sunday I'm making breakfast and my eggs come out speckled with gray bits. Looked awful. I figured my seasoning was chipping. So I wiped the pan down and ran my finger across the surface. Sure enough, rough patches near the edges. I remembered my grandpa's old trick from a visit to his place in Boise. Cut a raw potato in half, dipped the cut side in coarse salt, and scrubbed the pan with it. Took about 5 minutes of elbow grease. Rinsed it, dried it over low heat, then did a thin coat of oil. That was 3 days ago. Cooked bacon and pancakes in it since, zero flakes. The salt and potato grit ground off the loose stuff without wrecking the base layer. Anyone else use the potato method or am I old school here?