Quicksand Fans

Trying to find a copy/link to a German (?) documentary on quicksand.

It features a blonde gal in hip waders in a lab. She goes into a mud pit and the lab dudes record what happens.

Thanks!

I believe you are refering to an experiment that has been done on the show "Galileo" more than 10 years ago.
But there are also a few other scenes that i remember.

Maybe it's one of these (Youtube-links are down because of the flow of time, but it may help your search):
viewtopic.php?f=21&t=1624&p=13485
viewtopic.php?f=21&t=4570&p=35569
viewtopic.php?f=21&t=6137&p=45785
viewtopic.php?f=21&t=22367&p=138226

Thanks!