I use tung oil (not always but for finishing some projects so a pint lasts me nearly a year). When I am working on a project I always change from my good clothes into clothes I wear for woodworking (I work in an office where business casual means slacks and dress shirt). I also always shower in the morning before dressing for work. Yet the hypotheses at my office is that either a couple small wooden bowls are giving an oily smell 9 months after being completed that can be smelled throughout the area or the oil has gotten into my work clothes or skin. Honestly, I don't bath in tung oil. I get a little on my hands when applying it and I wash my hands afterwards. I don't drink it or use it on my hair.
I personally can't see how woodworking or tung oil could be the culprit. My office has no ventilation and the only air exchange takes place when the door is open.
I work in an environment where doors must be closed and locked when we are not there.
I previously ran a test where I removed everything from my office that was not issued to me by my employeer even the house plants. After a week the smell persisted. Then after returning everything to my office and running the AC unit (which provides only air circulation and no air exchange) 24 hours a day and even through a weekend did the smell go away. The building I'm in is nearly 100 years old and my office has no air exchange except when the door is open which I now can have open because of the smell.