Thanks for all of that, guys!
I have a LOT of Todd's pellets of various species, and really like the Pitmaster's Choice blend pellets for a lot of things. So I might try blendering some into dust. But the consistency might be better if I got the actual dust directly from Todd. Still, the tinkerer in me would have to try mashing some pellets, of course! :)
I wouldn't mind smoking longer if that's what it takes when using the dust. Or I could light both ends to double the output. I saw a YouTube video where the guy lit both ends and the middle to get four times the smoke output. Of course, then he had to add more dust and re-light if he wanted a longer smoke.
One of the things I really like about the pellets in the AMNPS is the rather long burn times I get.
As a more direct response to the original poster of this thread:
I will add that I have used ice cubes in a disposable aluminum half-size steam table pan one time when I was smoking some butter. It worked very well for me, and pushed the temperature in the chamber down by ten degrees or more. If I'd had a frozen water bottle or two, that would have been more handy, but just putting ice cubes into an aluminum pan worked quite well for me that time.
The pan was not covered, and I put it just above the AMNPS smoke generator so that the heated air rising from the pellets had to pass up under the bottom of that pan and then up around it. So it was in the direct path of air-flow/smoke coming up off of the AMNPS. It didn't drip onto the AMNPS, but it might have been fairly dry here that night. I don't think I have any notes about that smoke session (shame on me!).