In July 2014, we struggled looking for this "nudist beach".
Thanks to this conversation, we decided to ask the locals to explain us where to go to reach this beach. We finally found someone who explained us this (and it was clear enough):
When you go down to Elafonissos by car, after having passed many green-houses, you will get a sign on your left, to Sklavopoulos, take this direction. The road will then become a track; at the first intersection like a T, go left; a the second T intersection, go right, and then drive during around 1 or 2 kilometers, following the yellow arrows, until you reach a parking place.
We were surprised to see all people with clothes; so at the end of the beach, we removed out clothes; a few hours later, another couple joined us naked as well.