Pictures
show the feet of the lander have no dust on them. Why is
this?
Well think for a moment; how could the dust be above the
lander feet to settle on it? Any blast from the lander's
rocket would throw the dust down and to the side,very little
would land on the feet. There is no air disturbance for the
dust to billow around in.
Throw the dust to the side and it will go that way, it
won't come back to land on the feet.
ALSO... on the earlier Surveyor unmanned landing
missions, there was very little dust on the pads... and not
one said a thing.

Pictures transmitted from the Lunar surface
of the Surveyor foot pads show that -- just as in the Apollo
case -- there is little or dust build up on the footpads. In
fact, only when the Surveyors were commanded to "hop" on the
Lunar surface by briefly firing their main thrusters did any
significant amount of dust build up on the footpads.

What these images seem to indicate is that
it is entirely reasonable -- if not normal -- for there to
be little or no dust build up on the footpads.