Sadly, I'm a bit hazy on the whys. I just buy into the benefits long-term. I've seen my whole life as an investment. Even from a very young age, I sowed what I thought I might like to reap later on, healthwise. Made me a bit boring back then, but now the benefits are evident. Still, I believe it's never too late to detox and get yourself straightened out.
Coconut oil has phenomenal benefits for all aspects of the body, I'm discovering. It's antiviral, antibacterial, and, although a saturated fat, I believe it bypasses the liver and gallbladder and doesn't jam up the arteries, but goes to work in lubricating the joints and general body functions. My partners has already witnessed a day-by-day reduction of Arthritis pain in his shoulder since he started taking coconut oil twice a day. On the skin it can smooth out wrinkles and on the hair it kills parasites and stimulates regrowth.
As for the oil-swishing with sunflower oil, I got most of that from this forum actually and http://www.oilpulling.com, and have witnessed astonishing benefits in myself and in those around me. Sesame oil is good, but too heavy for me. Sunflower feels lighter.