147
Trying to find a Shul where only one person recites Kaddish is hard to find and even when you do there is no guarantee that a stranger wouldn’t enter in the middle of kaddish and start reciting it, which happened to me many times.
Another thing that can be done is that EVERYDAY give a small coin(it can be as little as a penny or as much as you want)to charity in the name of the deceased.