As I mentioned, I made a mistake when removing a cut piece of cast iron in my stack. A piece of pipe fell into the drain. It was about six inches from the wye in the concrete slab so I though I could just reach in and pull it out. But it wasn't there when I reached in. Anyway, I sent my shop vac down there and retrieved some small pieces (more fell in there than I'd thought, I guess.) I have just about the whole pipe, as I've tried to reconstruct it. I put a small magnet on a wire down there and that grabbed a few more pieces. I want to send a bigger magnet down there or some kind of scope to take a look. It's probably not such a big deal, but right now I have good access. I have a wye attached to the vertical stack with no hub couplings. I can take the wye out, or just thread through the 3" outlet on the wye. Any special tips, tools, or advice? I also want to be careful not to get the magnet stuck down there on the pipe. I was fiddling with one of those magnets people use to pick up nails in their workshop. It's attached to straight rod. There will be a cleanout there (and there's one on the wye set in the concrete floor, but the frame around the stack kind of covers it. I suppose if it catches stuff and creates a blockage I should be able to rod it out right there. Worst case scenario seems that I'd have more clogs than usual. Anyway, I'm looking for advice as it's been sitting on my mind.