Hmmm... interesting.

I suppose if you're not concerned about the loss and inefficiency of such a device (long tubes and pathways for precious spice to condense on), or the difficulty in getting the dose dialed in... that could be a lot of fun. 4 people vaping off the same rocks at the same time with the same instrument.  Yeah, I could imagine that that might tie the trips together. 

Everyone and everything in your environment contributes to the spice flash anyway.  From the artwork on the wall to texture of your seat... 

Thanks for sharing, and welcome home.