That's definitely not true. I've finished the first season and I'm halfway through the second and the worst is implied ecchi in one small, maybe 5 second scene and it's not even that bad. K-On even aired on Japan's Disney Channel.
Thanks! I'll check it out! What I'm looking for is something funny and really clean from start to finish. Like, K-ON get's close to hente when it is supposed to be cutesy and funny. I guess there isn't much clean anime, huh? :c