All-purpose cleaners won't remove rust stains from sinks, tubs and toilets, even with a lot of elbow grease. The trick is to use a stain remover like Super Iron Out ($10 for a 5-lb. jug). For toilets, add Super Iron Out to the water in the bowl, then clean with a stiff nylon-bristled brush.
I Took The #BizChallenge to Remove My Family's Toughest Stains - Cupcakes and Crinoline