Like I said get real, do the job properly as an Electrician would, imagine you have say 12 suitably sized cables that the mickey mouse strippers can accommodate, how long is your method going to take you? they are expensive gimmicks mate, nothing more nothing less, designed to take lots of pound notes from inexperienced people.I just tried it on some 2.5 T&E, it will happily do 8 inches in one go and you can still pull the sheath off easily.
The reason I said 3 inches before is that the more you strip off in one go, the more of a slight mark it leaves on the remaining sheath, so it's better to do more short bites, than one big bite. So if you want a really long strip, only the last one needs to be a short piece.
So, you could strip, say, 24 inches off, sheath removed also, in less than 5 seconds.