I had recently discovered and removed what appears to be Cabbage loopers on some of my kale, as shown in the images below. What is the best decontamination procedure after removal? Should I give the plants a thorough rinse and transplant it with some fresh potting soil?
The caterpillar that you have there is from the white moth. They are all over my garden. I literally harvested some lettuce + arugula today and made a salad and found about 5-6 of those caterpillars on the leaves. I rinsed the leaves with water best I could and enjoyed the salad.
I wouldn't over think it. I'm sure I've probably missed a few in my life and actually eaten some of those caterpillars. To reduce the number of caterpillars spray a neem oil solution on the leaves especially the underside of your leaves.
No point washing the plant or changing potting mix. You could look on the leaves and remove the eggs weekly (most likely on the underside of the leaves).
These are probably cabbage loopers. You can use the biological control Bacillus Thuringiensis, commonly known as BT. It is a bacteria that infects many caterpillars, causing them to stop eating and they starve to death. It is non-toxic to humans.