Adding a blur filter to a video using Avidemux 2.6.9

I'm creating a screen cast tutorial on how to process employee attendance and I want to add a blur to certain frames to protect the names and ID numbers of our employees but I am having trouble figuring out how to do this. I tried using a delogo filter but I can't figure out how to set it so it is only on for just that frame during that time period. I've attached a screen shot of my set up. Any help would be appreciated, including letting me know if there is an easier/better program to use for doing this. Thank you.

Easier program to do blurring? Avid. Easiest (in my opinion) After Effects. Both Avid and After Effects have a motion tracking tool that does the work of keyframing for you. I find the one in After Effects is more intuitive. With Avid you can use the paint tool and then a circle or square shape to create a mask. After Effects is similiar in that you just create a mask and motion track that to it. Creative Cow, Lynda and YouTube have some tutorials on this.

Thank! I'll check out both of those! :)