No lol your completely wrong. I've tried this over a dozen times and I've gotten great results. There's a science behind it. If the seed floats after you lets it sit for 30 minutes and then push it down then the seed is pre mature and won't grow. But if it drops it'll most likely germinate. And yes this method does just compliment the capabilities of a good seed, it also gives germination a better chance than if it were done wrong or by a different method. I've done months of research of just the topic of germination because I have a lot of friends that smoke and I'd collect the seeds from their buds; I've germinated hundreds of seeds just to germinate and then throw away and when I came across this video it gave me a whole new method and I found this to be the best method
So if they don't drop your method does not lead to 100% germination...
While yours are swimming or lying on a towel, mine are on its way within 24-48 hours
^This.
Also, if a seed is not mature, no it will not germinate in anything. You could this check by simply rubbing the seed between your thumb and forefinger. A bad seed will crumble, a good/mature seed will not even if you apply pressure.
Cannabis isn't an aquatic plant. Roots breath oxygen, even an emerging radicle/taproot. Oxygen doesn't dissolve very well in water, and less so the warmer it gets. While you
can start seeds between moist paper towels, you need to watch them like a hawk and fuss with them later. They'll also pop open in water if they don't rot first, still not ideal for the aforementioned reason. High humidity is also detrimental and can lead to damping off/rot. Some breeders explicitly advise against using paper towels.
Older seeds might benefit from a short soaking in water, because after a few years the embryo does start to dry out.
Otherwise, I don't see how water/PT is actually anymore effective than direct to potting mix in proper conditions. Potting mix holds water just as well as paper towels do, and also holds air, hosts symbiotic micro-organisms, has nutrients, etc. Direct to mix, under constant lighting is very easy, effective and doesn't require handling the tender sprouts later (set it and forget it). Typically seeds started this way, for me, (~95% of them) have broken through the soil, opened their cotyledons and put out their first true leaves after ~72 hours (as opposed to a day in water, 1-2+ days in paper towels, 1-2 days to pop up and longer to put out true leaves).
The only reason(s) I can think of that the PTM may
appear to be any more effective is that people are putting their PTM-seeds in areas more conducive to germing (e.g. warmer) than where they would put direct-to-mix seeds, or are afraid of keeping the potting mix properly moistened, having their lights on, etc. This makes some sense, because people often put their PTM seeds somewhere warm or have them insulated (on top of a fridge, cable box, gaming console, between plates wrapped in a blanket etc.).
No matter how you are germinating it cannot be cold, and for direct-to-mix it shouldn't be dark either. Seeds are covered by the mix (and so are in the dark until sprouting), and lighting like tube fluorescent fixtures can help warm the soil surface. It should be at least 72 (F) and warmer is better; warmth hastens germination more than whatever media it is you're starting them in.