I use Clorox to sanitize surfaces in a sick person’s room—mostly items that she will touch, such as the toilet, the rails on the bed, door handles etc. We are trying to use the bleach in a spray bottle mixed with water. The purpose is to kill C. Diff and MRSA.
The problem is: when I mix Clorox with Water in a spray bottle, the first spray is brown. This does not happen every time.
What you describe is a frequent issue, and the reason we do NOT recommend making/using a bleach spray solution. The sodium hypochlorite active in Clorox® Regular Bleach2 reacts with metal parts in the ordinary trigger spray assembly and basically creates a rust solution. One needs specially treated metal parts like those used in our Clorox® Clean-Up® Spray Cleaner trigger to avoid the problem. The longer the contact time for the bleach solution and trigger, then the more likely you are to see the rust solution. Obviously, the rust solution will NOT be providing the desired surface disinfecting you intended.
For your problem, a disinfecting bleach can be used as follows. Pre-clean any surface. Make a disinfecting solution (3/4 cup Clorox® Regular Bleach2 in a gallon of water); wash or wipe this solution on the surface; allow to stand for at least 5 minutes; rinse and air dry.
You could also buy the Clorox® Clean-Up® Spray Cleaner and use it according to label directions.