On my Lexus I have got nails in the Michelin Pilot Super Sports 3 times. Each time the tire pressure light came on, and I was experiencing slow pressure loss. I was able to top up the air with the compressor, drive to the tire shop, and get it patched.
My point is that I never needed the sealant. If you ever need sealant, you at fucked. It is a pain to get that stuff of the rims, and the sensors will be destroyed. It is a last resort in emergencies. That said, if you have a huge gash in your tire, I doubt the sealant will help. So it is irrelevant really.
FOR SALE: 2013 ///M5 Individual Click for pics and info
Monte Carlo Blue, Platinum Full Individual Merino, Platinum Alcantara, Piano Black, Exec Pkg, Drivers assistance pkg, Bang and Olufsen, 20" wheels