Continue to patch empty tubes. When the patched tube is reinflated inside the tire it doesn't matter that it looked deformed.
For a traditional patch kit, it's neither contact cement nor glue - it's vulcanizing fluid. Put it on the tube and wait for it to dry before applying the patch.
Stick on patches are supposed to be permanent - but many delayed failures have been reported. Hasn't happened to me, but I haven't used many.