Last summer I got the book, Naturally Clean Home, and have been trying a few of the recipes for cleaners out. Will post after I've put some to the test for several months.
Here is a totally natural cleaner I've used for years. It is pumice stone. I use a "Pumie" stick. You get it wet and then rub it on stains on porcelain. It is the best thing for cleaning the hard water build-up we have here. The toliet is clean without any chemicals. Just "Pumie" and a little, very little elbow grease. I've also used it to clean on the porcelain tub. It says it will work on the barbecue grill too.