Re: Tangiers Phunnel bowl... impressed, i am not
To be frank I have been smoking from a Tangiers small funnel for a long time and have never had an issue with foil being pulled into the spire. I use basic foil and a single layer. It really comes down to technique. If you don't use enough foil to cover the top of the bowl and the sides of the bowl then the foil may be pulled down by the air flow.
If you still have problems even doing that then use two layers. It will allow for better heat control and make it less likely to be affected by the draw.