This definition of patina that generally increases the value of antiques is quote from Pamela Wiggins (see photo below). She has been in the antiques business ever since she was small.
I clean off the verdigris (ex. belly hairs, bugs, intestine membranes, dried skin, blood) because it can give me a very bad infection if I accidentally get cut handling the item at live trade shows.
Most people avoid items that have been buried with dead soldiers like there was "bad luck" connected to it.
Still for the record any genuine photo examples of "blood rust" on bayonets would help.