Here is the first prototype of my new Cold Smoker.. The Guru Adaptor will be much smaller of course. I'm really pleased with how clean the smoke is.. The new version will have a stainless cup on the bottom to collect water and tars. This will add lots of versatility to your cooks.. with the adjustable air pump on low the unit hardly creates any heat.. I'm really looking forward to smoking many of different things.. My first smoked chicken was a hit with the family.. Never got this much
Definitely don't leave it in place unless in use. I haven't actually done the rubber washer thing because mine doesn't turn on its own anyway. Just surmising that if you found one that could take the heat, that would likely do the trick. Maybe something like this:
https://www.amazon.com/HIgh-Temp-Silicone-Washers-10-Pack/dp/B01J1V7RCM