Attila

Here is an idea for you if you want to avoid gluing to the pot:

Take a sheet of plexiglass (1/2 centimeter thick) and cut it to the spape of the bottom of your pot. Then drill the drainage holes to the right places to match the holes on the pot.

You can glue the rocks to the plexiglass and place the whole assemby into the pot.

I've never seen this but I don't see why it wouldn't work.

Regards,
Attila