Which character do you play with? Have you searched his/her forums for optimal wake up moves?
Across the board wake up attacks seem to have differing properties. I'm no expert on the topic; in fact, I do not understand the wake up system at all.
As Flash, my attempts to wake up attack get stuffed on the reg'. I held my tongue for the first week, trying to convince myself that I was inputing improperly. But now each time I am stuffed there is an accompanying verbal outburst. "Cabbage" is my favorite, although "bullshit", "garbage", and "stupid fucking game" often get used.
It seems to me that the most effective response to your inquiry would be to say: don't get knocked down in the first place. Thus you won't need wake up attacks.
It's cabbage IMO.