It has only one real use: vs sleepers who you want to RO or get position on, or are off axis. It will only work once a match. Maybe even once per player.
Basically, you need to put them in a situation where you know 100% that they're not going to tech or roll. They have to be completely asleep at the wheel or at least in severe brainfreeze.
An example is post 1A+G, B+K. During the ground stun you can dash up and apply your mixup vs tech (2b+g for the rock doom combo or whatever you want). If they're wise to that they won't tech, giving you a GT openning. Problem is, they're head toward. So if you want your forward RO you need them to be feet toward, which is easily accomplished with 1k, 3a+g. Like I said, this will only work if they're trying to avoid the low throw and maybe mashing bbbb to escape the more damaging 1b+g option. If they wait and roll they can still get out.
Good luck. I've managed to land it about once per person I play against, always in casuals where I'm fucking around. If I see a chance at the next tourney I will definitely make someone look like a chump though.