Doc wrote:

"That was how the garden shop suggested it be applied.

I think they were wrong. The weed cloth served as a barrier between
the vegetation killer and any seed that dropped on top after you did
the work.

I don't like weed cloth anyway. It's a real pain a few years down the
road when you decide you want to do something else with that space.
For example, you decide to plant a few perenials in amoungst all the
rocks in that area -- getting that weed cloth out of the way is a real
pain. And in a few years the weed cloth is covered with dirt, so it
serves no purpose anymore.

I guess I'm trying to
make the dirt as inhospitable to living organisms as possible. Perhaps
something in the dirt as well as on top of the cloth and rocks? "

wrote:

I think you're making it a lot harder than it has to be. I've used
Triox applied on top of a crushed stone driveway, no cloth. One
application in spring kept just about all the weeds out until at least
fall.

I agree, you're making it much harder than you need to. Don't bother
to remove the rock. Just apply a vegetation killer on top of the rock.
You'll need to do it once a season, but 7' x 20' isn't that large.