Sealing a leaky seam on my epdm roof.... what should I use?

Don't see it in this thread, but elsewhere I have read NOT to use silicone. I also use it for everything under the sun, but people here say it is not the way to go. I have used the Dicor self-leveling sealant in a tube (like caulking gun) and it does a great job, but not too pretty. But then its on the top, so you're the only one who sees it!