How did you train your kitty to the scratch post? A treat for every time they show interest and scratch it? I have a sisal rope one now, but he's shows no interest in it. What is better or do cats prefer more..the sisal rope posts or the carpet posts? I'd hate to use a squirt bottle to discourage him from scratching the sofa. He's just starting to trust me and I'd hate to freak him out by squirting him...Any tips?