I think part of it is the exfoliation that the scalp receives when it’s shaved and while the hair is coming back in. A lot of hair thinning seems to be due to accumulation of dead skin cells that may clog follicles. I’ve tried baking soda, but the aspirin exfoliation looks interesting:
https://www.healthline.com/health/beauty-skin-care/exfoliation-for-scalp
Thanks for the link. I’ll check it out.