Question
Could I put a plant on top of a brick that's on top or inside a water-filled growing tray to keep the soil damp while avoiding water-logging?

Answer
Hi John,

If a pot is sitting on a brick, it won't get any water at all.  That will prevent water-logging, but unless you regularly top-water your pot, it will dry out too.  

Water-logging is best achieved by just keeping the water level in a tray low, or regularly top-watering the pot.  Since you didn't mention what kind of plant this is, I can't comment on whether or not it would be appropriate for that species.

Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.growcarnivorousplants.com