Actually I am using a bag of them in my smoker. I have a BRINKMAN trail master horizontal offset.
I was talking to a guy in Home Depot last year and he said that he was using 3 rows the length of his CC about an inch apart.
I grabbed bag. I tried different combos with them since the way he said he arranged them didn't work for me!
I have messed with them by moving them around in different configurations so as to attempt to distribute the heat evenly!
After adding tuning plate moving tuning plates and even removing and adding some in conjunction with the ceramic briquettes.
I even used the briquettes between the tuning plates for hot spots in an attempt to even out the heat and it was helpful but not the answer completely!
I ended up with a configuration on my tuning plates and was getting much less heat at the stack end of my CC. I took the briquettes and put them in a tight not closed position just under my stack on the lower grate.
Not sure why but for now and over the last 3 or 4 smokes, I have temps within 2 to 7 degrees difference from the SFB end to the stack end!
I suppose it deflecting the heat back under them before the heat leaves with the smoke out of the stack!
For right now they are there and I don't want to move them since I am having success controlling the heat at this time.
I do think that they could serve to control your temps. I also bought a second bag with the intent to try just the briquettes, but haven't even opened them yet and wont until summer.
They are cheap enough that your not out much trying them for yourself, if they don't work, gift them to friend or neighbor with a gas grill.
I have also seen ceramic tiles, 4x4 x 1/4" I think, and the had like 100 little holes in them all the same size. They came 8 tiles to a box.
I think I figured it would take at least 3 boxes just to see a possible difference but they were like 12 or 15.00 per box of 8. They did look like they had promise but I was still holding out for a cheaper solution and I think I found it with the briquettes and some trial and error along with my tuning plates!