thanks for all your responses but now i am more confused than before. i guess since i am a klutz i will try it.

There are a number of Youtube videos that demonstrate the Slide Lock ruler. They helped me understand how it is different from regular rulers that have a handle.

I use my Slide Locks as in the videos. However, I also use them on top of other rulers -- something the videos don't show. This is probably because of liability concerns. In other words, I will prepare as if I am going to cut with one of my regular rulers, and then just before cutting I place the Slide Lock on top of the ruler and press down. It keeps my hand up and away from the cutter and it also helps keep the underneath ruler in place while I cut. I even do this with my June Tailor Shape Cut mats! I place the Slide Lock just to the left of the cutting slot I am using, moving the Slide Lock for each cut. I find this helps keep the mat from sliding around.

Edit: There are others, but here are a couple of links to Youtube demonstrations of the Slide Locks:
https://www.youtube.com/watch?v=hYOoRetnlfM&t=106s
https://www.youtube.com/watch?v=e-VKvtILhKE&t=54s

Mine's never been out of the box.

The dots, film or tape you use to keep the ruler from sliding will not prevent a cut from the rotary cutter. You can glue a ruler to the fabric and still get a bad cut. Word of caution: If showing a beginner how to cut either at home, class, quilt shop, or guild, if the beginner was not instructed to use a safety device, not have one for her to use while there, and to use one with no exception to cut with a rotary cutter there could be a lawsuit if the person gets a bad cut.