Practically? Very easy, just remove the <Sinking/> tag.
It will dc you anyways.
Code:
<Ground type="0xbf" id="Quicksand">
<Texture>
<File>lofiEnvironment2</File>
<Index>0x08</Index>
</Texture>
<BlendPriority>3</BlendPriority>
<Sinking/>
<Speed>0.6</Speed>
<Animate dx=".1" dy=".1">Flow</Animate>
</Ground>
