All Dewey nylon coated cleaning rods are male threaded. Male threading allows for a significantly larger amount of nylon to adhere to the rod due to the heat involved during the coating process. This makes for a longer lasting, more durable cleaning rod. Also, the male threads allow for a stronger connection with the rod attachment. This is particularly important in larger calibers where a heavy jag being supported by a small, male thread can snap off and plug a female cleaning rod. When this happens, it is very difficult to remove the material from the tapped hole and the rod is destroyed. If a jag snaps off in a brush adapter, the problem can be solved for only a few dollars.
The nylon coating provides a soft, protective surface that is designed to protect the bore during the cleaning process. There will be contact that is unavoidable during cleaning, particularly on longer rifle barrels. The nylon coating ensures that this contact will have no effect on the barrel.
It is recommended to use a rod guide whenever possible. They are designed to help protect both the firearm and the cleaning rod at the same time. The action area on many rifles contains sharp edges that can scratch a rod if contact is made. A rod guide takes those edges out of the equation while centering the rod down the bore.