I’ve decided to keep in depth posts on body electrotherapy separate from brain stimulation which includes neurostimulation.
TENS Unit - Transcutaneous electrical nerve stimulation
Mixed experiences on this thread starting 2013: a bit of help while it’s on, say quite a few.
Putting the unit & left over wires in a pocket helps, said Loveandfaith.
First time I heard of the caveat of not going close to the heart as she says.
However all electrotherapy triggers my focal seizures, that’s my caveat. Similarly @SK1 said they ‘shoot her right off the table, even on low’.
May deflect some of the pain sensation, according praps to the Gate Theory of pain that only certain amount of pain can be sensed, so some is overridden.
As the thread title from 2013 says (Does anyone know why TENS units are being discontinued? They are such a wonderful alternative to pain meds): jdixon was very worried having definitely heard multiple times that they were going to be completely discontinued. @Sheila_W found out at least that it was ‘only’ some (20) brands at that time. Renie’s ideas were that maybe they were going to be combined with other electrotherapy like EMS and that insurance companies were no longer covering them. She also found an ultrasound machine for @Petunia_Girl. Sheila: did you ever try it? I can’t remember it being named, but think I might have had some at some physio somewhere. jdixon said they hardly worked.
A link to conductive garments by Waterswaves Conductive Garments | Garment Electrodes | Medi-Stim, Inc. shows an addition to a TENS or similar electrotherapy units (Muscle Stims, Interferential, Microcurrent, and High Volt Galvanic) for people who have skin reactions from the electrodes or need a larger area treated, siskiya names suppliers as well as massage machines that she compares to TENS (probly very different tho), and also says it’s worth having one extra, as they can break, also recommends acupuncture, unless it ‘hits a nerve’. Sandi1 has the tip of wetting the sticky gel & keeping it in the fridge. The most mentioned brand was EMPI.
As TENS units are still being used, without being combined with anything else, the problem seems only to be the insurance one, due to lack of sufficient evidence. EMS is for stimulating muscles, not for blocking pain.
It doesn’t just work 1) by nerve stimulation (competing sensory neurons at the pain perception gate), but also 2) by the release of endogenous opioids.
Tens unit update Powerful, so low settings, <35$.
@rosebud74 got a paingone tens pen after it helped @Sheila_W, but it was too hard to use and treats an even smaller area than a normal TENS unit. The conductive garments mentioned above might be the right thing for you, rosebud? (@Lmd added that as opposed to TENS/electrotherapy you can get acupressure type pens that may help ‘at times’.)
PEMF (Pulsed electromagnetic field therapy)
2018 Pulsed electromagnetic field therapy in the treatment of pain and other symptoms in fibromyalgia: A randomized controlled study - PubMed Didn’t appear efficient for FM.
Comment on: Pulsed Electromagnetic Field Therapy in the Treatment of Pain and Other Symptoms in Fibromyalgia: A Randomized Controlled Study - PubMed / https://onlinelibrary.wiley.com/doi/10.1002/bem.22224 Comment argues that might’ve been due to electro-smog?!?
Pulsed electromagnetic field therapy - Wikipedia
Germany: BEWEI = radio frequency therapy, i.e. PEMF at radio frequencies
(My wife just pointed an electrotherapy form out in a German newspaper ad, with a sort of brand name BEWEI, where it says “also called radio frequency therapy” and is combined with lymphatic drainage in a cosmetic studio, but is also or comes from pain/osteoarthritis treatment. Which is extremely funny considering that BEWEI stands for BEauty WEllness Innovation! 
Only reputable link I can find is a German neurosurgeon who claims it’s normal for pain, whilst the English wikipedia Medical applications of radio frequency - Wikipedia it implies that radio frequency (RF) therapy is part of PEMF, which can also be at extreme low or ultra low frequencies, ELF, ULF.
Just have to add here that I like the abbreviation PEMF as it reminds me of EMF’s (only real) hit “Unbelievable”.