I used to do that but now I had my spin fixed for every slot I play. I only spin 100x, win or lose, hit the scatter bonus or not, I move to another slot machine. The reason? To avoid that one more spin can sure hit the scatter fallacy. A uniform number of spin approaches in playing slot games isn't the best strategy but at least it enables me to avoid such idea.
I observed that hitting the next scatter or free spin bonus takes a random number of spins. I experience hitting another scatter in 1 spin after hitting the previous scatter but I also observed that the reward in bonus spins tends to diminish after playing a long time in the same slot. I know the reward in bonus spin is random but it can't help because that is the way I experienced it.