I buy the disposable aluminum loaf pans at the grocery store. I bend up the "lip" at the edge so it goes straight up, then snug it right up against the side of the wood box. You only foil the top of the wood box, so there wouldn't be any foil between your water pan and the wood box. No water pan needed for poultry. I agree with Gregg that your St Louis ribs probably went too short, not too long. They might not have been tender enough, so they seemed dry/chewy. I also go 6 to 7 hours at 225 for St. Louis. 4.5 to 5.5 for baby backs. Remember to wrap in foil and rest for at least 30 minutes when done.