I don't know what a freeze frame sequence is. Sounds it is a bunch of freeze frames tied together, or it could be a video that plays for a while and then freezes.
In the first case you might want to try posterize time, which would make a video jump say 10 frames at a time.
In the second case, you would move the CTI (Current Time Indicator) to the point when you want to freeze the frame and then go to Layer > Time > Freeze Frame.
If a freeze frame sequence is something else please give us an accurate description or example.