I've never understood the concept of a self-cleaning oven. I picture this invisible hand appearing and scrubbing it clean. Where the crumbs and other food bits go is beyond me. But this I do know: We need the deep-cleansing of the Spirit of God using the Word of God in our hearts and lives. We cannot do that ourselves.
We need the Spirit to invade every nook and cranny of our hearts, like butter filling the crevasses of an English muffin; permeating, filling, comforting, lavished upon the dry crust of our souls so thirsty for the life-giving Spirit.
Jesus, in Matthew 23:25-26 said the Pharisees cleaned the outside of the cup and plate but they were filled with extorting greed and excessive self-indulgence. He said they needed to clean the inside (heart attitude) so that the outside (observable actions) would be clean and pure. He highlights our need for God's cleansing mercy and forgiveness. He highlights our need to stop trying to figure everything out to our own advantage. It backfires on us and we lose. He wants our motives to be pure. Only He can bring that about. Go to Him and tell Him your trouble. He cleanses hearts and changes lives.