I think due to how everyones bodies are different, and how each of us have varying levels of CF progression and body chemistry in general, some will have more pronounced blood thining than others, when given the same doseage in the same way. When I was going nutty with the stuff both in pill form, drops under tongue, and inhaled, I did notice I had pronounced blood thining when i would get a cut, or pick my thumbs or lip or whatever that would draw blood. Nothing rediculous like hemophilia, just added time for it to clot up. Some people might take 4 drops and have more noticeable blood thining, and others won't seem to have any. A daily vitamin K supplement seems to counteract the thining effect to a large degree, and as CF's, we all should be on a daily vitamin K supplement anyways.
If your lungs are generally unhealthy (well all of ours are, but some worse than others), and you have inflamation or a possible infection at some stage, and you take any antiplatelet substance (blood thining), even aspirin, it could result in blood streaking in your mucous. Also if you move out a good deal of mucous, it can reveal nasty stuff you had stuck in your lungs, like plugs, old blood, etc. People also notice this with HS. Like I tell everyone, if you choose to start taking the stuff, do it for a good month atleast, and keep tabs on how you feel during that time and note any changes good or bad. As long as you don't have any prolonged problems like more bouts than usual with bleeding over a period of time, way too much irritation, etc etc, I'd say keep at it for a month to see if it benefits you. A few people didn't like it and quit, and others have stuck with it and are enjoying better CF health.