May I suggest a different design?
One of the reasons to foil pouch your chips is to force the initial bitter acrid "gas" that is released from the wood down into the burning charcoal to get burned off and get cleaned up.
When wood is heated the first volatile organic compounds released are gasses.. this is why you have a flame over a log in your fireplace. The hot gas raises up, mixed with the available air, when the fuel air mixture is correct it bursts into flame. If there is not enough air to burn as a flame it creates a thick grey/white/yellowish vapor/smoke with very large sticky droplets. This is the smoke that burns your eyes (imagine alcohol mist) and sticks to your hair and clothes making you smell like a forest fire.. This is NOT the material you want condensing on your food. It is absolutely bitter and acrid. My hypothesis is that most back yard chefs mistakenly use this smoke.. I base this on how ridiculously sweet, loaded high fructose corn syrup most commercial BBQ sauces are. If you mix bitter acrid with ridiculously sweet you get a "tangy BBQ flavor". Nothing I want to eat..
if you make a pouch and put just 3 or 4 holes dead center and place it facedown in the hottest part of your burning charcoal.. this will force all the gas down into the heat hopefully burning off most of this nasty gas leaving you only with the secondary vapor with has the clean flavor you are looking for.. I roll a doubled up sheet of foil into a cone, fill with wood, fold over the top sealing in the wood, then tear off the bottom of the cone. I then carefully open a hole in the burning charcoal and carefully drop in the cone.. this gets the gas even deeper into the burn zone.
Or you can purchase the KK Hot/Cold smoker which uses an aquarium pump to create vacuum which keeps the wood smoldering.. when smoldering it never gets the wood hot enough to turn the wood alcohol to vapor.. it just burns slowly as it makes contact with the burning area. Dripped cast iron pots work too..