I've clean a few TBs as well and have found the ONLY way to clean them is to COMPLETELY remove them in order to clean the BACK side which is where all of the filth is.

It's that simple.

Does anybody clean the throttle bodies on the newer cars as preventative maintenance. Some techs recommend every 50-100K as schedule for cleaning service.

Yes indeed the airflow meter, which I have referred to in the past as the throttle body, does need cleaning. If it is left to get fouled, it will get sticky and cause a poor idle.

I have never used any chemical. I simply wipe it all down with a nice clean shop towel. I wipe all around the side and then push down the flap far enough to clean the underside of the flap around the outer edge.

I noticed an improved idle the first time I ever did this because it was pretty dirty. Since that time I have KEPT it clean, so I didn't notice anything after cleaning.

Good luck,

A tech I know uses his old toothbrushes to clean out the TB :)