I've cleaned 2 or 3 tanks with various degrees of success, none of them getting anywhere near as clean as a new one. The one I'm currently using has 3 fuel filters between it and the carb. If the repops fit, just buy one. If you do decide to try cleaning it I would recommend not using rocks or gravel. Use chain, nuts and bolts, anything metallic so you can get the last few out with a telescoping magnet if needed. The last 2 or 3 rocks can roll back and forth for hours before finding their way out. Ask me how I know this.