Not sure this will have any material effect. Bowlers don’t spit on the ball. A couple of Suth Aafricuns have been rumbled using mints or other chewable but that’s unusual.
Of course, if you want to get a cricket ball to swing, sweat is the best and legal means to get the aerodynamic asymmetry required, if you can’t get your hands on a bottle cap, or lip balm, or sun screen or pomade etc.