Good slo-mo starts with how you shoot it. If you shot a low shutterspeed and 24p, you’re hosed. If you shot a low shutter and 60i, you might be able to pull some slo-mo from it.
Converting 60i to 24p for a final render won’t help you either. It only makes challenged footage worse.
What is the source? how much reduction are you using?
Douglas Spotted Eagle
VASST
Certified Sony Vegas Trainer
Aerial Camera/Instructor