They work
But you do have to round the right angle edges(scissors)-and tape the edges and ends
I use duck tape
and you have to get the hang of reinstalling tubes-and pushing the liners to re-center them.

For those who say they don't work-gotta ask WHY?
If the answer is the sharp edge and ends- DUH- no kidding!!
Tape them-fabric rim tape-old fashion 1st aid tape-or duck tape or even package tape -gotta take the edge off them-and tape them