It's got me out of trouble before.
There are different brands of it under different names but it's all similar stuff, it just runs in liquid form inside your tyre then once a puncture occurs it will plug the hole and solidify.
I used it a few years ago when i had a slow leak on a tyre that had a decent amount of tread on it so thought i'd give it a go.
Pro's: Tyre literally stays the same if punctured. I rode a few miles to a tyre place with a nail still in place with the tyre fully inflated, after i'd heard the pop of it going in, then the noise of the nail on the road.
Perfect if you're going touring or somewhere obscure where a puncture could be troublesome.
Con's: Can be tough to get inside the tyre, you'll need a proper airline, and something to poke down the valve as beads of rubber can jam it up. It's certainly not as straightforward as just pouring it in.
Nobody will repair a tyre with this stuff inside, it's way too messy and time consuming to even attempt to fit a plug for example.
More people are born because of alcohol than will ever die from it.
I'm not sure if there is an issue of balancing the wheel with this sort of stuff in. Plenty of people use it without any apparent problem but getting the wheel balanced BEFORE you put the sealer in would seem the sensible thing to do. I imagine when the wheel is spinning at speed the liquid will be evenly distributed, but could be a problem trying to balance the wheel statically or at a low spinning speed.
It also claims to plug holes 15mm wide, so that would obviously be a judgement call to get that sorted as that is one big hole, plus i wouldn't want to going at high speed with tyre damage like that.
I would imagine a tyre fitter would frown at the stuff, but don't see why they wouldn't put it in for you?
Certainly wouldn't hurt for touring purposes though.
More people are born because of alcohol than will ever die from it.
I don't know about the sealant stuff but I have just repaired (I hope) a puncture caused by a ruddy great screw by plugging it. Ill let you know in a few days how well it works.
a bird in the hand poops on the wrist