Tires liners do work, some claim that they make the wheels feel heavier but I think the difference is very small.
You need to use a ligher or candle to heat the end so it softens and loses the hard edge which can cut a hole in the tube if left as is.

Also the liners do not last forever, should be replaced after a year or so since they will eventually crack along the length and rub a hole in the tube.