You might get some added cooperation from your son by using rewards, but he probably won't become fully trained any quicker for it. Usually, kids get trained when they are physicially and emotionally ready. They will do this in a matter of a day or a week when they realize they WANT to be potty trained, have all the necessary nervous system and bladder development, and will generally proceed without any rewards beyond the satisfaction of achievement. Just like learning to walk and talk!
This was my experience with my daughter decades ago, and her experience with her son. And it's been the consistent experience of several young families in my religious community who have let their children lead the parade, whose children all trained quickly and without stress somewhere between 2.5 and 3.5 years (with the exception of an autistic boy, who trained much later).
Most boys (yes, there are exceptions) won't pull it all together until they are approaching three, or even a year or so later. A toddler who reaches that stage of maturity at, say, 30 months can be "in training" for a year starting at 18 months, or he can pretty much train himself in a week if they wait to start the process at 30 months, when he shows interest and eagerness.
"Pretraining" is always useful; describing, demonstrating, stories and videos, role-playing the activity with toys, practice sits on the potty, and even occasional accidental successes. Keeping the activity light and attractive and completely free of stress will encourage kids to want to achieve as soon as they can.
