Ah yes, the nasty red stuff. First of all, be very careful with things that work "too good" like Whink. They can take the finish off of porcelain fixtures along with the rust stains. Also, never, ever, mix with bleach or bleach containing products. You can get dangerous fumes produced and you can also "set" stains that will never come out. If your toilet has stains that won't respond to anything else a pumice stone will rub them out but again dull the finish (you get pumice stones at Home Depot and such). Iron Out and other powders like it are very good. You can add them to your wash water if your white clothes are getting red spot or just do it once in awhile to lift that veil of yuck that accumulates when you aren't even aware of it. You will be amazed how white your clothes get. You can also sprinkle the powder in your toilet water periodically, let it set a little while then brush. It does a fantastic job. Finally, I had a water softener man tell me once to sprinkle it over the salt pellets, no real formula just a little here and there, as you put salt in the tank. It helps keep your softener clean without having to buy the pellets with added rust remover (which he claimed has too much of the added stuff anyway). I've lived with this problem for 30+ years. It is a royal pain as you are finding out!
"When you are in love with someone you want to be near him all the time, except when you are out buying things and charging them to him." Miss Piggy