Yep, I finally stopped being... well, Me, and got an
AMNPS. <link
That is the tray, uses Pellet wood fuel. Convenient and widely available locally to me.
It can also be used with 'dust' (sawdust).
It can be used directly in your Smoker/Oven, or with a mod for cold smoking like cheese and almonds, up to anything you can stuff in your oven.
Mine filled burned for 11 hours straight with Hickory Pellets in it. (Break in run)
Here is mine, as it is final. Guys use metal mailboxes, popcorn tins, or whatever you can figure out. But the end result is a smoke generator totally independent of the oven's heating element, and capable of using Pellets or sawdust.
My last batch was a combination of hickory pellets as a 'fuse', and Alder dust over it. Made a nice mild smoke that lasted longer than needed, and was a very pleasant aroma and fantastic taste.