I have. I used to visit this guys apt. he had this wall he would put up in the front hallway. i would go in, suck his very fat dick, take a big hit of poppers, turn around and back up. He would eat my hole and made me squeel like a hungry whore....then he would fuck me and that too felt amazing.
Yes, a few times around here in L.A. Some were plywood with a hole, some just sheets. And most were good experiences, except when someone had a TV going (distracting), or there were weird smells, or it was too darn hot in the house. Oh, and then there was the one another guy showed up unexpectedly, felt kinda weird.
I've had terrific one-way deep and steady sucks, but my fav is when the other guy stands up and lets me enjoy a few strokes as well, then we swap back and I'll shoot in their hot mouth! A couple of times the guy's been up for piss too, which was hot. And a couple surprised me by backing up onto my cock. I'm rather visual, so that kind of didn't work for me.
All that said, it's been over a couple of years since I took advantage of one. The ads dwindled down to just a couple of regulars - "jocks" who wanted only shaved young cocks (not me). Now that CL has dropped personals, no way to find out about one. (PS STDs are on an upswing here in the L.A. area, so it wouldn't be smart to go for the video arcade holes. I've done that, too, some years ago, was fun in its way.)