I don't foil and I've never injected a butt. I do use a water pan though to create a moist environment. I also like to use a mop but that's more for layering of flavor than moisture.
Lang 36 patio
18.5" Weber Smokey Mountain
22.5" Weber OTG with Cajun Bandit Conversion Kit
Char-Griller Akorn with side cart
1999 Weber Master-Touch - bent but not broken
14.5" Weber Smokey Joe Silver