Apparently quicksand isn’t as deadly as we have been led to believe. While we may be sucked in rather rapidly, humans are apparently not supposed to completely sink into the muck. Getting out, however, could very well be a difficult process, as the more you move the more you agitate the mix, making it more and more challenging to get out of this predicament. Still, it’s refreshing to know that it won’t kill you. Unless you are on a beach and the tide comes in. Then it could get ugly.
On a somewhat related note, we were oyster, uh, fishing (oystering?) many years ago in Washington State and I recall that my dad got stuck in an area of the mud that just didn’t want to give up the boot. He eventually slid his foot out of the footwear, leaving it for the tide. I have no idea if it was quicksand, but it certainly sounds similar. Glad he gave up the boot instead of waiting for the tide to come in.