Recently, I was able to find a pre-owned Attain device at a discounted price and have now played with it some.
The "probe" is very interesting. Mostly, it's silky soft silicone rubber, but has two stainless electrodes, one on each side. Deflated it's about 5/8" in diameter and 5" long. If you inflate it outside the body, it swells to about 1 1/4" x 3/4" in cross section. The length remains the same. This is roughly the same size as someone poos.
The instructions say to apply a "dime sized" blob of their conductive jel to the tip of the probe before insertion. You probably need a bit more. Rectal insertion is fairly easy lying on one's side with knees drawn well up, as to receive an enema. I found that just pushing the probe straight in doesn't work. You'd need to pre-lube the opening if you're going to push the probe in directly. I found it necessary to push the probe in a bit, withdraw it, then push it in further. This is repeated until the probe is fully in you. At this point, relax and enjoy the feeling a bit.
Now it's time to play. Turn the unit on and inflate the probe. Inflate it to about the middle of the pressure range. The probe feels like a soft butt plug and is really quite comfortable. I felt little tendency for the probe to slip out.
When the probe is comfortably in you and has been inflated, turn on the e-stim. It starts very mildly and you can barely feel it. As you increase the intensity, each stim caused your butt to contract around the probe and you can see your butt cheeks pull in. This happens completely out of your control. You simply cannot stop the strong clenching. The sim continues for 7 minutes, then stops.
At this point, you are instructed to clench your anal muscles and release in response to visual prompts. The bar graph indicates how much you squeeze.
In summary, whether it helps with pee and/or poo leakage is unknown, but it feels pretty good. Used alone, I have not had any urge to poo after a session. I intend to try it to see if it increases the feelings from a powerful laxative suppository, because the involuntary muscle contractions should intensify the laxative effect by rubbing the suppository against my bowel wall. Time will tell.