I hear this over and over about balls for heavy oil. Leaving aside for the moment the question of exactly what heavy oil might be, why is it necessary for a ball to "make a turn?" The one and only time I've ever encountered what was, without question, heavy oil (so heavy you could barely pick the ball up, it was so slick) I used a ball that made no turn whatsoever. On "rooster-tail" oil, for at least 48 feet I used an El-Nino Wrath and finished second in an eight gamer. Played straight off the outside to the hole. All I asked was that the ball tilt a bit before it hit - it didn't have to "turn" to carry.
Seems to me that folks need to get over the fixation of covering boards/turning to really learn to play the soup.
--------------------
"To plunder, to slaughter, to steal, these things they misname empire; and where they make a wilderness, they call it peace." (Tacitus)
"If one tells the truth, one is sure sooner or later to be found out. " (Wilde)