The only BBQ'd Cornish Hen that I've had was excellent and was from Cosy Corner in Memphis. I have no idea how they cook it, but I wouldn't be surprised if deguerry doesn't see this and venture an opinion on what they do.
You'll never go wrong following Landarc's advice though.
I am very interested in how your cook goes and will stay tuned.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle