The reason is that iodophor is mainly used to sterilize wounds that have been injured, so if you apply Yunnan Baiyao after killing the bacteria, it will cause the drug ingredients of Yunnan Baiyao to enter the wound, which is bacterial and may lead to infection. This is not advisable as it may cause the moisture to penetrate deeper into the wound and lead to infection in the deeper parts. The main purpose of Yunnan Baiyao is to relieve blood stasis, swelling and pain. When applying it, you must choose skin without a wound, if there is a wound, you must not do it.