I've had my teeth whitened. It was to make my teeth match in colour (they had been discoloured due to antibiotics which I had taken as a teenager to help my severe acne) and my health insurer paid. So maybe they are the best judge of what is a medical need (yes I am privately insured with a non-German insurer). It won't give me a movie star grin but it looks, in my own personal opinion, better.
Acne is a medical issue, it can be painful, cause scarring and disfigurement (I'm not talking here about the odd spot by the way). By working with a dermatologist, I managed to limit the amount of scarring and now have healthy skin. By seeking early medical treatment for a medical problem long-term issues were avoided.
Friends and relations of mine have also had so-called "cosmetic" surgery for medical needs, breast reductions to protect their backs, ladies rid of their moustasches (caused by hormonal imbalance) by laser, nose corrections to help with breathing...
To dismiss such procedures out of hand is short-sighted (and you can have that corrected by laser, well the short-sightedness at least).
I could have millions of operations and still not look like Heidi Klum. Mind you if everyone looked like Heidi Klum, that would be dull too. And does everyone want to look the same? No, but a desire to be your best inside and out is not a bad idea.
I like my teeth straight, healthy and white, I like my skin clear and healthy and my self-esteem is just fine thank you.
Kza, I hope that, for your work colleagues sake, your desire to stay true to your natural self does not extend to not washing or not using deodorant.
Andy, here are a couple of sites which might interest you, not specifically Asian Spas but still possibly helpful:
Just Pure - day spa and products based on moon-phases
List of main spas near Munich
Ludwig Beck Hautnah