[dice]

Where I have a hole with a piece of perforated pipe under it
but no net pot for it, I just stuff the landscape fabric down the
hole and pack it with the same container mix used for the whole
container. It makes the landscape fabric kind of bunched and
wrinkled around the hole, but so what. It works, the container
mix on top packs it all down flat around the lip of the hole, etc.

On most I use the net pots (I was ordering some kelp meal from
an online hydroponic store anyway, so I added a half-dozen net
pots to spread the shipping over more stuff), but on the ones
where I just have a piece of perforated pipe under the hole for
the wick, the "landscape fabric wicking chamber" does work fine.