the very first BBQ series on TLC in 2005 or 2006 outed Johnny and his blue bottles. Unitl then it was only known by those that payed attention at contests and watched Johnny or Mike Davis in the morning hours. Of course you missed a lot of what they did in their motorhomes.
Then Mike and Debbie did a class and the rest is history. There's lots of posts over the years and if you do enough searching on different boards you'll get some pointers.
I personally use about 6 bottles at a contest. And I also use ICBINB spray in my big spray bottle for basting while cooking. Spray is more liquid that squeeze.