Track Slow down object

I have a question I want to track an object in a video using mocha pro and then apply an effect that slows the object down in the video. What effect would I use, would it be a sapphire effect or an continium and which one.

I can slow down the video I just want the object to slow down not the entire video. I figured I can track the object and then apply an effect. I am using Avid or After Effects.