“My white clothes look dull and dingy. Most of the labels say “NO Chlorine Bleach” – is there another way to whiten them?”
There are many reasons for whites to become dull. A very common factor is hard water. The trace elements in the water can prevent soap from lathering properly and the residue can leave a dull or gray appearance. Check with your local utility to see if this is a concern. For slightly hard water, it is possible to overcome the problem, by simply adding more detergent.
You can try an all fabric bleach (Bleach for un-bleachable), or an oxygen bleach, but always test for color fastness on the clothing, and add the bleach to the soap and water, BEFORE adding the clothing. Even these ‘safe’ bleaches can cause damage if poured in concentrate, directly onto wet clothing.
You might also try soaking in a solution of water and lemon juice overnight before washing. Then add this soak water into the wash water with the regular detergent when washing.
The final tip would be to hang these articles to dry in the sun. The sun is an excellent natural bleaching tool, which can actually even lighten some stains to the point they are invisible. The other huge benefit of air drying, along with the fact it is free, is that stained clothing will not have the stain ‘set’, whereas a tumble dryer gets so hot, that the stains are baked into the fibers.