puncture repair kit effectivity

Question
Hi,
I found in my cycling material a "puncture repair kit" for cycle tyres (Brand B'Twin; it is something under pressure) that is supposed to to "heal" your tyre somehow;  no need to glue any patches it seems to say.
I had not the opportunity to test it (if you are out there you want to use something that works for sure).

Could not find any information on internet on how it works and if its effective, and if so; what time it takes.  
Any experience with this kind of thing ?  

Answer
Hello Ronny,

Thanks for asking these kind of interesting questions, I love those.
Besides the brand, there are similar kind of "sealant's" on the market (like http://www.cantitoeroad.com/catalog/product_info.php?products_id=117 or http://www.no-flats.com). The last one has some nice video's how it works.
I have some experiences with these range of products.
Joe's seals are very good and interesting.
It works very easy, you have a liquid in your innertube. By inflating this to the right tension there is created a vacuum.
When the outertyre is punctured by a piece of glass or stinged by bramble-bushes the liquid will find a way to the whole/outside.
The air outside will harden the sealant so the punctured whole will be closed by the sealant.
But remember that this still is a repair. Change your tyre fast before you will ride the bike again!!!
Joe's offer a whole range of these kind of products, but why do you want a liquid in your tyres?
When you have bad luck and you have a lube inside your tyre, and it will blow after hitting a rock (or something like that) you can imagine what can happen...
Use latex innertubes, they are more expensive but will give you more comfort and less trouble with airleaks.

Good luck and enjoy the video's.

Mike