Different ways
You can apply the soap in several ways. First, you can scrape the soap with a cheese slicer, or grate it. Be careful not to let the grated pieces of soap just fall into the sand.
You can also break the soap, but just using the whole block works well too. The important thing is that the soap does not touch the ground. What works well is to attach your soap to thin bamboo sticks. For example, attach a pair of tights or socks to the stick and put the bar of soap in there. Hang them as close to the ground as possible. Wait a few days, and you will see that pests have not dared to come near your plants! Who would have thought that soap can be useful even in your garden!