The major issue I see with this product is price point. For $350 you can buy the well established Weber Smokey Mountain cooker:
18 inch for $299
22.5 inch for $399
The consumer will know they can return it to a store for a refund if they dont like it, also they have Weber's excellent warranty program. The final thing is that the Weber looks very attractive, your product looks like a big cooking pot with mud lining the inside.
I hope you take my opinions as it was intended, constructive criticism.