What is the best method to install the tacky glue in a metal wood head to stop the rattle? I’d prefer not to remove the shaft and drill into the head through the hosel yet hate to drill a hole in the body of the head.
You mentioned the two methods that are the options. Either you can go through the bottom of the bore in the hosel or you can drill a small hole in the sole of the head. Sometimes if the head has a weight installed, either removable or not, if yo remove the weight it may be open into the cavity. If not, the best option, in my opinion, is to drill into the sole of the head. It is easier to control where the head tack goes by drilling into the sole. You are adding a few grams of weight, so you want to put it in the best area, generally low and rearward.