And this newspaper ad from 1970 shows you could have them for a mere 77 cents at your local drugstore!
So what makes these curlers so great? In many ways they combine the hair smoothness of magnetic rollers, the ease of setting, tension and drying ability of brush rollers, and the comfort of sponge rollers. The bristles on these rollers are thicker and spaced further apart than those on similar plastic rollers of the 60s and 70s and there are no sharp edges to catch and damage the hair. So while the bristles help secure the roller like other brush rollers, the hair does not really get caught and them and instead lies on the roller itself between the bristles, more like a magnetic roller.
In spite of the coarser bristles, they are still as easy to set as any other brush roller, if not easier. The soft plastic and rounded shape of the ends of the bristles really adds a new level of comfort. Like foam rollers, they flex a little. If you wind your hair neatly and secure with two piks (see image below) you can create whatever desired level of tension is best for your hair, and because the rollers bend slightly, you can easily adjust it across the length of the roller (contrast that to hard plastic Wil-hold rollers, where if the tension is slightly off, you will end up with a roller close to falling out or uncomfortably tight).
So what are they really like to use? Easy and quick to wind, and also easy and quick to secure neatly with plastic piks, and because the air flows though them, easy and quick to air dry or dry under the dryer, and quick and easy to unwind for a prefect result. They are even nice to wear - wound the moderate, even tension they stay in perfectly all day or all night if needed, and you just feel so nicely set all the time. No loose curlers falling out or tight ones yanking. Definitely the best curlers ever! To bad they don't make them any more.
Careful: Like most brush rollers, if you have longer hair and use smaller rollers and don't wind or unwind them carefully. you can easily end up with a tangled mess. I have heard stories of rollers having to be cut out of hair to get them loose. If you have longer hair, experiment with one or two rollers and see how they work for you, and/or have a friend who can better see what they are doing wind and unwind them carefully and neatly so they don't get tangled.