I own and use one, and find that it effectively helps to release trigger points. I haven't heard of electrical point stimulators being used to locate or stimulate acupuncture points, though I can see how it could be possible that trigger points and meridians may intersect. EPS devices can cause nerve or tissue damage if misused, thus it really is important that anyone using them be properly trained.
Sharon Sauer, CMTPT, LMT and Mary Biancalana, MS, CMTPT, LMT teach a series on myofascial trigger point therapy techniques here in Chicago - and I
believe that their training includes use of EPS devices, but I am not certain
http://www.myopain.com. Mary Biancalana and Chuck Duff also offer advanced Thai massage training called Clinical Thai Bodywork at Thai Bodywork School of Thai Massage in Evanston, IL, where I am receiving my training
http://www.thaimassageschool.net/thai-massage-class-ctb1.php.