Watching an interesting video of old style sand green where you have to putt on
Made me think that this "green" are the same as some of the so called "greenside sand traps" some muni course have. It has hardly any sand and is not deep. For these" so called traps" conventional teaching of hitting sand with the ball will not work. There isn't enough sand underneath the ball.I think think the sand wedge will just hit the ground. The best way to get out of these would be to putt or a "picking" type of chip shot.
There's a hundred year old, sand green, nine hole course near the cottage we rent in Bruce Beach, Lake Huron. It has a hole that rivals anything you've ever seen ......on a real course or on a calendar. Its beyond description........a tee that is a birds nest in the trees which you have to hike down a valley to get to. You shoot through an opening in the trees no more than ten feet wide to a green that is one hundred and eighty yards away and a hundred feet below you. A sunken coffee can, some oiled sand and rake. The green is no more than fifteen feet wide.