Heat shrink tubing vs Shrinkies

I bought clear, 1/8", dual wall, heat shrink tubing with a 3:1 shrink ratio from cableorganizer.com. I used a flat iron to put them in. What I didn't like was that once I had shrinked it (using the highest heat setting), the bond still wasn't small enough for my liking. I removed them by using the flat iron, and yes, they slid right out. There was the glue residue left, which was very hard to get out and I didn't like that at all. From what I've read, the "adhesive" is actually the inner wall of the tubing that melts when you apply heat. I know some people have used cableorganizer.com and liked the results. I don't know if shrinkies are a little different, but I just wasn't impressed by the whole method period. It was difficult to hold the piece of shrink-tube in place over the natural hair while simultaneously inserting the pre-bonded strand AND positioning the heat source.