So this particular theory's been rattling me poor brain for a while so I figured I should probably let it loose. It starts with the assumption that flame sealing is real in the Katekyo Hitman Reborn Universe, but not necessarily as a bad thing.
In this theory, there are two types of sealings: permanent (known as 'true sealing') and temporary (referred to as 'barrier'). Temporary flames are when there might be physical/dangerous sideffects to allowing an active flame be active. For example, active Cloud Flames in a young child has a higher risk of cancer if the flames are turned inward too often to speed up cell regeneration in healing.
For temporary flames, lightening flames are the best bet. Because of their natural defense usage, it's not that hard to transfer that to surround the inner flame and stop the child from unknowingly using their flames. Temp Barriers are also easily removen -especially by the person that put them. Downsides are: it wears down and ties the person creating the barrier to the person using the barrier.
Since flames need to be constantly outputted, eventually a temporary barrier will wane and need to be renewed. It's best that the same person do it, but not required. By making a barrier, you're essentially putting a piece of your soul into someone else's so it only makes sense that you'll be tied to the person. While the barrier is there, you will sense changes in their flames and vice versa. Even when the barrier is gone, if your flame was used as a barrier for long enough the barrier receiver's flame may still bear the imprint of your flame.
On the other hand, we have permanent sealing, also known as 'true sealing'. For these ones, rain flames produce the best result. While temporary sealing cuts off the natural reflex to call for flames, true sealing cuts flames from coming to the surface entirely. It's similar to being inactivated except a typical life-death situation isn't going to reactivate you. You'll need an extraordinary life-or-death situation to reactive your flames.
True sealing acts like a sedation medicine. It puts your flames to sleep and makes them hazy. The receiver of a true sealing may feel a drop in strong will but there aren't many affects to your personality or anything like that. The danger of true sealing comes when you try to undo it.
Since the whole point of true sealing is to make sure your deactivated, reactivation is a whole other beast. Like I mentioned before, you'll need a extraordinary life-death situation but it's not the only way. Of course, you could use a Dying Will Bullet (Trademarked by Vongola) but for most people, you won't have access to that. So what do you do? Another solution is to expose the sealed flames to many active flames in an attempt to get them to notice and wake up.
Similar to inactivated flames, deactivated flames respond to environment. If the environment is flame-heavy (meaning many active flames) then the deactivated flames my activate themselves in an attempt to fit in.
What do you all think? This is my first really thought out post so any discussion is appreciated :D