It is, and I've done my fare share of buried sand tickling. But from the clips I've seen the girl is rarely ever ticklish which makes it uninteresting to watch.
I agree. I love this concept as it is so natural and the person is so helpless and restrained. They just need to find an extremely ticklish person so that is is not a disappointment. There was a really good one on YouTube over 10 years ago but it is long gone now.