You can't save files in older versions of AE. I believe however, that Peder created the original project in AE 6, so he may have an old version for you. See if he chimes in. In the meantime you could always try yourself.
a) Create a large solid
b) Enable the 3D switch.
c) Create another solid layer at full composition size
d) Apply Particular
e) Set the emitter type to layer grid emitter
f) Assign your 3D solid as the emitter
g) in Particular's "Options", increase the grid density
h) Back on the main interface set Velocity to 0.
i) Find the "Turbulence" in the "Air" dynamics
j) Tweak a few values until your particle grid shows visible deformation
k) Animate the Turbulance to make it 4D (the fourth dimension being time)