Compliance is low and enforcement non-existent. Thailand taxes only remitted income not (yet) worldwide earned. Most countries would have a double taxation agreement with Thailand which enters the computation ensuring that only up to the highest tax bracket of both jurisdictions is paid and not paid twice. Personally i make sure i do not become a resident for tax purposes nowhere else but the home country.
You can do within Thailand as long as you have at least 2 weeks left on the current tourist visa (exempt / extension) but applying from outside and especially home country is so much easier…. At least as I assesed at the time in my case after enquiring with two IO: Jomtien and Sriracha.
body wash and washing up liquid? I see aisles and aisles of it at supermarkets …. I usually buy natural and biodegradable … this washing up liquid is certainly very good