Location: Zu San Li (ST36) is located four finger widths down from the bottom of your knee cap, along the outer boundary of your shin bone. If you are in the right place, a muscle should pop out as you move your foot up and down. https://exploreim.ucla.edu/self-care/acupressure-point-st36/
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Method:

Where can you buy a moxa stick?
https://www.ebay.co.uk/itm/New-10-Years-Traditional-Moxibustion-Sticks-Smoke-Chen-Moxa-Roll-Sticks/264256863215?hash=item3d86efbbef:g:YB4AAOSwSlZbzobm