Now you can Forget Venturi Type Cold Smoke Generator
Venturi type design is nothing but to introduce extra fresh air to cool down temperature of smoke.
Now you can build a cold smoke generator by using two fans.
One is for burning wood, the other just blows fresh air into smoking cabinet.
Just find a metal pipe, fill it with saw dust, blow from one side, the other side is inserted into smoking cabinet. Then it is smoking generator
In your WSM, just put a can on top of one air inlet, fill the can with saw dust. Then it is a smoke generator. Insert second fan to another air inlet, it simply blows fresh air to WSM to lower the temp. It is easy to do it in UDS too.