I have the ABS Pitt-Boss, but the two units are similar in design. As for water in the smoke box, I have done it both ways and I did not see any difference.
This is some of the information I got from Jeff Wilkinson:
With the front door open, the damper open full and the stack open to approx. 1” start your fire.
Start with a couple handfuls of lump coal or briquettes in the middle of the fire box. Fill a chimney with the same and start your fire let the chimney go until it is 2/3 white hot. Dump the coals, and cover with a couple more handfuls of unlit fuel.
Once the charcoal has all started to turn white, about 10 min. close the fire box lid; leave the front door open for a couple more minutes. Close the front door and let the temperature regulate at 225-250. Adjust the damper and firebox slides to get this done.
Add a couple handfuls of charcoal every 1 – 1 ½ hours as needed to maintain temp. Make sure to clean out the ash after each cook, the bottom of the firebox needs to be clear so air can circulate around the fire.
This is a good place to start. I have now made an expanded metal fire basket and I fill it with Royal Oak and several hickory chunks.
I will be happy to discuss more ideas.