I'd avoid quicksand at any cost. A few years ago my DAC was swallowed whole, never to be seen again. Tragically, this incident occurred in clear view of my grandkids. Counseling can get very expensive.
In the sand box
I have 2 audio buddies who have built component sandboxes with different types of sand. They claim Beach sand is the most dense and made a huge difference when the turntable and amp were set in them. Has anyone else been down this road? I mean there are several ways to isolate equipment, this is just one of many.