Since no one else with experience with EMDR has responded, I'll say what little I know.
My current therapist (she has specialized training/experience with gender and trauma issues) is trained in EMDR and has been doing a little with me.
From what I can see, it needs a lot of preparation work. That is, you don't just walk in the door and have somebody doing the beeps or whatever the first day. I think you need to develop a trust relationship with the therapist (well, trust is one of my big issues, anyway.) She had me come up with mental images that would give me a sense of safety, happiness, etc. (There was one I simply couldn't do -- I couldn't think of anyone who I would feel safe with.) And we talked about a lot of issues.
In my case, it so far hasn't brought up much in the way of forgotten memories as forgotten feelings. I expect it to be a slow process because whatever it was that happened to me, it's had 50+ years to fester.
FWIW, my previous therapist (who was very good, just not trained in my particular issues) says that some of her patients have had good results with EMDR.