Quote Originally Posted by JOSarff View Post

Would this be solved by doing a run of AgCl in one vessel, AgBr in another and mixing the product? Or did I miss the boat at the dock?

This will not work properly. The halides will begin an exchange that might give you the same thing every time, but you would not know what you had exactly which is the basic problem with Cl/Br making. And, the explanation requires a lot of chemistry! That is a major reason to avoid this can of worms.