In case you didn't know, the photo in this article shows a couple 8-week old pine seedlings soaking in rooting hormone after having their tender young root cut off completely with a grafting knife. You might be thinking: "That sounds like a good way to kill some pine seedlings", but you'd be at least half wrong.
The "Seedling Cutting" technique is now a standard among avid American bonsai enthusiasts, and is fabled to reduce the height of the finished tree and increase the swelling at the base from a very young age. A swollen base is a good thing because you want a fat trunk in "serious" pine bonsai and short compact branches. It might seem a bit odd if you are into horticulture to both sabotage the seedlings natural habit and then dunk them in a rooting hormone, but the technique has proven to be quite popular and can be quite effective.
In any endeavor people will experiment, document and find a variety of ways to reach the goal they seek. With bonsai hobbyists you will find an avid group of people who like to tinker with their plants; like to make a slow process faster, and like to seek methods for improvement. Bonsai can take a long time, but it is the fun had along the multi-year journey that bonsai hobbyists find so interesting and fulfilling. If you become a bonsai hobbyist (rather than a plant parent or a "bonsai parent") then you might have dozens or hundreds of bonsai, and work with them endlessly to create a result that is both different and unique.
If you choose to start tinkering, our advice is to make sure you have more than just a couple plants. Bonsai can be really fast growing given the right conditions, but if you are still learning how to care for plants then take your time, do some more reading and just have fun along the way!