Nothing sticks to the foil. The foil is just to keep light out of the container and it goes just over the lip. It does not line the glass.

Cover the glass between uses and CCG won't set, so I just keep using it until I need to add some more.

CCG come in many formulations, even a flexible option and 3 thicknesses. Use whatever works including knot sense if that is your choice. I'm just saying the way I use CCG and it works for me. If you are able to control the knot sense so that you get the right amount in the right thickness in the right place all the time, that is great. I don't think I could get it around and over the thread, but not in the eye of the hook using the the tip of the knot sense tube. I'd still have to sharpen a tooth pick end to apply it.

For the fly below, I don't think you can coat just the fly and thread to the hook eye and no more with the knot sense squeeze tube. You'd still have to essentially "paint" the fly whether it was CCG or knot sense. So it depends on what you are tying.