With most characters from 30-60 percent ICs can do a Popo d-throw Nana fair into a desynced ice blocks lock. It's really easy to do and the opponent has a really hard time teching it (if they can at all, I haven't completely checked yet though they probably can). Anyway, it will do up to 24 damage and completely un-move deteriorate your other attacks. So not a bad idea really. Also at least with some characters you can do this odd lock where they're like coming into you instead of moving away. This is done by holding forward after the fair. Being able to do this is pretty sweet because it will guarantee that no matter where you are on the stage you can maximize the lock. Cause it allows you to lock forwards or backwards.
Edit: Another thing. If your having trouble with keeping the desynced the ice blocks. The best method I've found is to continually tap the b button fast and what will usually happen is Nana will start to go slightly faster of Popo slightly slower. Anyway there not doing it at the same speed, so right after you hear Popo saying the HYAA thing stop for an extremely brief moment and continue again. It takes a bit of practice, but that's whats working for me.
Edit: Another thing. If your having trouble with keeping the desynced the ice blocks. The best method I've found is to continually tap the b button fast and what will usually happen is Nana will start to go slightly faster of Popo slightly slower. Anyway there not doing it at the same speed, so right after you hear Popo saying the HYAA thing stop for an extremely brief moment and continue again. It takes a bit of practice, but that's whats working for me.