As documented, fantastic orgasms are possible with e-stim. I have build some electrodes out of spare anal plugs of varying sizes by attaching insulated copper wires (you can't have a copper allergy and use this device, but stainless steel wire can be used) in grooves cut in the plugs. By positioning and sizing the electrodes one can create a small conductor in a pattern or over specific spot, like the G-spot. If you add a clitoral hood electrode (folds over the clitoris and can use a pierced clitoral bar for retention, or merely taped on for the un-pierced subject) you can direct the dial in current at medium voltage or high voltage and nil current, between the G-spot on one side and across and down the bladder neck and anterior into the clitoris. Subjects who received this treatment reported a sensation of extreme arousal, a sensation of clitoral swelling, a profound urge to void, and spasmodic orgasms that caused heaving pelvic contractions, squiring of both urine and periurethral glands (female ejaculation), loss of visual acuity, breathlessness, helplessness and a sustained orgasmic state followed by collapse when the voltage was turned off. All in all a very gratifying electrostimulation experiment. For those skilled in the art, a urethral electrode at ground and above ground electrode in the vagina and on the clit can be used. The possibilities are endless if you add an anal array electrode that fires forward across the colon wall and the septal space to the base of the uterus and posterior vaginal wall.
As always, play safe. Reasonable currents, avoid burns by using electroconductive or ultrasound gel, no currents across the torso or arms or head to foot, but ok on same side -- ie no pathway that might depolarized the heart in cardioversion or defibrillation, that works well in Judicial Execution, which unless is your fetish, you don't want to simulate. (That is a whole other topic altogether!)
Next plan is an electrode under the testicles of the male with a current pathway to the G-spot of the female..... if you get my drift. When proper conductive lubricants are used the pathway of least resistance will be perineum to perineum, but this one can be tricky and not for the faint of heart, literally and figuratively. If you are a fringe electro-stim user, you will understand the risk to benefit ratio of this practice.... Have fun!