Q.How To Get Rid Of Volunteer Acacia Saplings?
I don’t have any pictures of these dreaded saplings. Each day I must inspect my soil to remove any new acacia saplings
Certified GKH Gardening Expert
It seems that you are doing the best thing, already, if there are other things in the ground that you do not want to kill, nearby.
If the area has nothing important that you don't want to kill, then you can try boiling water to kill them off. Here is an article that will help:
https://www.gardeningknowhow.com/plant-problems/weeds/boiling-water-and-plants.htm
You can also try solarizing the soil. This article will help: