Yeah, you can save it sometimes. Some people advocate more throttle, but if you are in a real tank slapper, it's almost impossible to hang on to the bars, much less twist the throttle. Don't brake, don't try to keep a death grip on the bars, just try to ride it out. Sometimes as you gradually decellerate, the front end will stabilize of it's own accord. If not..see above post. I know a guy that got into this after landing a wheelie at probably 120 mph and left S-shaped black marks down the pavement for 140 ft (measured), and saved it. He tried accellerating, but it just got worse. When he let off and relaxed, it stabilized, That was on a Suzuki Bandit 1200. (Not stock by any means.)
The best thing is to avoid situations that cause tank slappers and put a steering stabilizer on.