Hey sorry if I sounded as if harness are totally a bad thing!
I just had a bad experience and it freaked me out

Harnesses from a young age probably work well! as we know that's the best time to get them used to things. I did it too late, so was my own fault I suppose

I now wish I had harness trained my 2 current cats from an early age. I'll think I'll just leave it now. They are really mellow, so I'm sure they wouldn't go far if I were to let them in the back garden... supervised of course!