<------- is the brisquit master. but have not done it in a grill, hence why I have 2 smokers at the moment. I'm busty at work but I'll type this up realy quick, its dirty and spelling is horrible but you'll get the idea. I'm also working on a web page dedicated to this already but its not done.
but if your wanting to try it, heres what your going to want to do.
go to costo and get yourself a brisquit flat. it's a good way to start, you dont need a "whole" you dont need a whole at this point.
take it home, rub it down with mustard, and spices. the spices are up to you and theres plenty of recipes on the web. I buy mine from a spice shop in galena.
wrap it up in aluminum foil and throw it in the fridge over night on a thursday night. on friday run over to gander mountian or maybe ace hardware and get yourself a bag of hickory chunks. they are usually forsale near the charcoal. you will soak these in a bucket full of water for a few hours before cooking commences. also buy yourself a wireless meat thermometer.
now friday night, around 9pm get yourself a few beers, a bag of chips, and some ranch dip, cause it's gonna be a looooong night.
take brisquit out of fridge and unwrap, insert meat thermometer to center of thickest portion of meat and put meat on grill. constant temp of grill should be about 225-230. no higher!
using a grill will be tricky, especilly a gas one, make sure you have an extra tank handy, your going to be cooking for roughly 1.25 to 1.75 hours per pound depending on internal temperatures. with a 10 lb brisqiut you do the math. thats a lot of gas. get that bad boy to one side of the grill and get yourself a metal pan to put wood chunks in, that will go on the heat side of the grill. do not use aluminum foil grilling pans for this, it will desinigrate after that many hours.
also se the timer on your phone and sleep on the couch, I want you up every 1.75-2 hours to flip the brisquit and brush it down with some melted butter mixed with a bit of brown sugar and rub spices.
lets talk meat temperature, there will be a point in the night probably around 4am where you will think you are going nuts, cause the internal temp has not moved and in fact may have dropped a bit, this is normal as all the fat is melting inside the meat. just be patient and the temp will start climbing again.
Once this beast gets to 200 degrees, internal temp, take it of wrap it up in foil nice and thick, then some old beach towels and stick it in a cooler to rest. heck I even throw an old pillow on top just to insulate it even more. let that puppy rest for a about 3 hours. or untill the internal temp comes down to about 170ish
now you can take it inside, unwrap it and unveil it to your adoring fans.
Serving, some people like to slice it, some like to pull it. my entire neighborhood likes when I take 2 forks and shred it for sandwiches. I shred the whole damn thing and stick it in the crockpot to keep it warm or serving. and yes the whole neighborhood knows it's brisquit day as they can smell my smoker going all night, by the time lunch on saturday hits, they are starving and standing by my front door.