Hm.. a quick search on google turned up a fairly critical wikipedia article.
EFT has been labeled as pseudoscience in The Skeptical Inquirer magazine, based on what the journal describes as its lack of falsifiability, reliance on anecdotal evidence, and aggressive promotion via the Internet. Gary Craig, the developer of EFT, has argued that placebo-controlled studies of EFT are impossible, because tapping anywhere on the body will manipulate "energy meridians". Skeptics have asserted that such an argument renders EFT untestable via the scientific method, and therefore a pseudoscience. This argument is also addressed by the Waite and Holder paper, in which the participants tapped on a doll, rather than themselves. Other critics have suggested that EFT's successes are likely to stem from "characteristics it shares with more traditional therapies", rather than manipulation of energy meridians via tapping. A recent article in the Guardian suggested that the act of tapping parts of the body in a complicated sequence acts as a distraction from, and therefore can appear to alleviate the root distress.
So... my diagnosis is that this technique is no different than when we psyche ourselves up before lifting, and therefore are able to achieve a new PR or get in more reps.
As we all know, your strength is effected by your state of mind, motivation, etc, so if you do something to get your motivation up, you can experience improvements in performance. This EFT thing might work for some people for that kind of thing, but personally, I'd rather just go in there, growl at the weights for a few seconds, then start lifting.