Finally !!  After looking for these for a couple of years now, a company has developed and manufactured a bi-polar silicone urethral insert. We were able to purchase a limited supply of them, as they are being introduced to the market.  This insert is a 6mm diameter, soft silicone insert that has two conductive strips built into the entire length of the electrode.  Additionally, although it comes with a 2.5mm audio jack with TENS pins, you can use your own lead wire as long as you have TENS pins or a suitable adapter for the leads you already use.