One of my toilets isn't flushing correctly. The drain pipe is not clogged. It appears to be the main flush jet (the smaller hole in the bottom of the bowl adjacent to the drain hole). I've tried liquid plumber. I've tried scraping with a coat hanger (doesn't seem like anything is up there). Any suggestion? Can I pour liquid plumber in the overflow tube? Maybe CLR? Any plumbers want to come over and school me on toilets?