I have seen them used and I personally don't think they are worth it. I use a sleeve ham type of thing for the same purpose . The sleeve ham elevates the fabric more and there isn't a chance of getting a pucker or wrinkle while ironing. The strips really don't elevate the material enough for a lot of people ... I saw where one woman ironed in her mistake while not paying attention.
That is my preference. Others may not agree, but it works for me. Also I can easily find my colored sleeve ham with a quick glance.