www.e-stim.net

Has any tried inserting the tuning in penis urethra and if so where would pad placement be for best result

I have been told it is impossible to smooth the inserted edge to a degree that it causes no longer injuries. The surface of the urethra is extreme sensitive. I tried to chamfer the edge with a pencil eraser and it still damages the urethra. The only solution might be a perfectly fitting polished tip as commercial products provide it.
The placement of other electrodes and the depth of the urethra one depends on what you want to achieve. I'm still testing and get interesting results every new combination.

I use a cum thru plug and Jerry rig a wire to it. This works well with a small anal plug quite intense.