Well I have thousands of pairs, made, tumbled in 2 different media for a nice finish, black half sphere plugs in one end and packaged in anti-corrosion bags. They are 3/4" not the 1" you mentioned. That seems to be the prefered size. I also have alligator to banana plug cords for them, in case you are making units with standard banana jacks. Around $10/set with cords, depending how many you want.
OR, I have nice already built "mini zappers" with permanently attached flexible cords to alligators packed with afore mentioned pipes, for $29.95 Hardly worth building one at that price.
I also have the same thing with belt clip, low battery LED, removeable standard banana plugs, with either pipes or wrist straps, as well as a 3 frequency (15/2,500/30,000)with higher output and stabilized wave. All are quite reasonable and very well made.