You can buy the strip at Wickes. However I don't think it would work on
the edges of the doors if that's what you are suggesting, it would just
pull out of the groove.

I could route a groove in the frame but I am not sure how to do the bits
near the ground and the corners.

I guess the reason behind a strip pulling out of the door and not pulling
out of the frame is some sort of 'physics'-type reason. What if I were to
grip-fill the strip in?

Colin