As I recall it was an 80 period MA. Long above, short below
Also (again from memory) once price cleared the 80ma, he used fib retracement levels to signal additional trades. The gentleman suggested that this technique allowed him a second chance to enter long or short, even if price spiked through that 80 ma.
Of course you still need a stop loss, but you should be able to get that through testing or observation of the max adverse excursion for your target market.
I think you're going to need an additional filter and some entry rules for this one to work, and the fibs don't test well, at least not in my experience.
I wouldn't trade it.
Good luck
Steve