  If possible, use those ones on only one hive, and monitor carefully. The general wisdom here is monitor closely for one year, at the end of that year you can relax some, but at the end of year two you can consider the hive as clean as any other hive.  It's probably most likely you will not get an AFB infection but if the worst happens and you do, please come back to the thread and let's know, it will be useful info. You could also come back and say, if you didn't get AFB.  I followed your initial post regarding the windfall of your used equipment and your obvious excitement at acquiring such used equipment. It became apparent after looking at your pictures of the used frames stacked up on your post that you would like to find a way to feel comfortable to use these old frames and incorporate them in your operation. Once you factor in the cost of scraping the frames, dipping them or bleaching them, and then repairing them, you are left with one sure result. You have a bunch of used frames on your hands. I am not even going to bring up the subject that they might have been AFB contaminated when you purchased them, or that they might still harbor AFB spores after you clean them. That is up to you to decide as you balance what your time involves vs. purchasing new frames to utilize in your cleaned up boxes. One thing is sure, if you do purchase new frames you will at least know for sure that they are clean. Generally people burn them and move on, don't fool around with someone else's used frames. Once AFB manifests itself in an apiary it's very difficult to eradicate. I guarantee you that you will lose 00x or more the value of your woodenware after you have no choice but to start burning boxes and frames to clean up your bees if it does present itself. Bottom line is that frames are so cheap in the big picture. Isn't your operation worthy of that practice?  "Tradition becomes our security, and when the mind is secure it is in decay".....Krishnamurti  