IDK, but if they did reach the bottom, they would be tiny. I didn't realize that it is 7 miles down. :)
Your fleshy parts would probably never reach the bottom, but once they rotted away, your bones certainly would. Bone density is about 3 g/cc, and sea water density at the bottom of the trench is about 1.08 g/cc.
Denser solids will always sink in a less-dense liquid.
They could....in the belly of a Great White.
Eventually their atoms will individually travel virtually everywhere.