William,
You most certainly CAN play a shot out of ice plant. As Spyglass Hill had significant amounts of it during the years I caddied there, figuring out the play from it was required. John has step one close, but you want the SANDWEDGE face almost totally wide open. Step two is a stiff-wristed, pronounced forward press with the club hovering 4-5 inches BEHIND the ball. Take a three-quarter back swing and slice through that ice plant with EVERYTHING you have!
The force of the heavy club, as the WIDE OPEN club face slices UNDER the ice plant, but not digging into the rootbase or ground, explodes the ball up and out of the verdant soup. The forward press usually always prevents the club from releasing too early and robbing momentum.
Several years back I was caddying in the AT&T for Wayne Watts, chief legal counsel for the host company, and his second shot on Hole #2 at the Glass found the heavy ice-plant, short left, about 20 yards from the green. Using the very method described previously he executed a beautiful recovery to about 12 feet from the pin...to the total amazement of the pros and other caddies watching there. One of the tour caddies blurted out, "ONLY a local caddie could have possibly known how to play that shot!" How true. I've pulled that type of shot off many times, as have dozens of other players I and other PB caddies squired around those courses on the Peninsula.
Personally, I liked the ice-plant, though it was a bear to recover from and if it was really down...you just take your medicine and accept the penalty and drop. The extensive removal has certainly made Spy play easier, particularly those early holes. From a playability standpoint, the resulting sandy wastes are fairer, but that ice-plant hazard was a unique feature there that is/was kind of cool.
Cheers,
Kris