If you are looking for something to really stimulate the urethral canal, give one of these soft silicone inserts a try.  They are made for soft silicone with impregnated silver particles, which makes these Electro-Catheters extremely conductive.  There are three diameters to choose from; Small (1/8"), Medium (3/16") and Large (1/4").  Each insert is 6" in length.  

These are Single Pole electrodes, so you will need another electrode placed elsewhere to complete the circuit.  Banana sockets are embedded into the top durable plastic T housing for a good solid connection.
 
You don't really have to insert these all the way to enjoy toe curling, electrifying results.

To order a Small or Medium size, go back to the Urethral Inserts page  and click on the size that works best for you.

NOTE: Lead wire not included, picture is for illustration purposes only.