I'm wondering about these pain pumps. Any experience or suggestions greatly appreciated.

I would be targeting the physiological response to neurogenic nerves more than neuropathic pain. If I can get my sphincters and surrounding area muscles to relax, the neuropathic pain would be greatly minimized. I have a urostomy and colostomy because of these clinching muscles - the urethral sphincter closed so tightly onto the indwelling catheter that fluid could not pass through it. We tried a suprapubic tube, but the bladder clinched so tightly it plugged the holes in the tip of the catheter, and fluid couldn't pass.
Normal bowel care was impossible because of autonomic dysreflexia during digital stimulation.

We have bypassed these autonomic dysreflexia causing problems via urostomy + colostomy, but the problem of clinching muscles persists. I feel this as both extreme physical pain, and extremely exacerbated neuropathic pain.

Any ideas on this method, and if it could possibly stop these muscles' clinching greatly appreciated. What kind of drugs are used in these pumps?

I've tried lots (tons!) of meds that mostly just made things worse, and have settled down to this:
Gabapentin - 3600 mg per day
Baclofen: 80 mg per day
Diazepam: 20 mg per day

I might note that spinal block completely relieves these pains. Also, for my urostomy surgery, a spinal catheter was placed, for five days post-op. It kept me from going into autonomic dysreflexia, and in fact, worked so well that my doctors called it "encouraging" and "indicative" that this procedure might work for me. This is in my records, and I have asked for follow-ups many times over the years, but am always given contradictory responses.