Must've been hell dirty I reckon. I've got it cleaned multiple times, as I'm OCD about it, but never made a difference to idle RPM. It's supposed to self adjust. At max, even if it was really dirty, it should be back to normal within a week. If idle is high on cold engine, lower on warm engine and higher again when you switch on AC (which I'm assuming is the case here) then IAC is fine.
I've had my fair share of problems with IAC in my previous Mitsubishi 4G13 and 4G18 (which are notorious for these problems) but never had any issue with any Honda. Have heard stories of everything going haywire in City, Reborn, etc. but personally never had any issue with multiple times throttle body cleaning on R18, K24 and even L15 Turbo. Stumped. Idle should be 650, when warm, maybe 100 revs higher when AC is on.