I've been doing some reno work in my house and I've used some ENT (Cor-line, smurf-tube, etc) in certain cases.

Anyone else do thing this? Seems to be working out good for me

I have and its ok, but pulling rope is way quicker than having to fish and pull in individual conductors.By the way watch out for the temperature limitations of carflex. And not to be exposed or out in direct sunlight.