irastus,
Your post was not too graphic...this one will be. *LOL*
I shit in a collander so I can inspect and see exactly how many stones come out and what they are like. My other tool for inspection of the stones is a disposable chop stick. I stir the full collander, flush the toilet with the collander sitting in the water, and keep doing this until all that is left in the collander is stones. If I did not use the collander I know I would miss seeing and being able to inspect my stones.
I use the plastic kind, with a handle. It fits into the toilet bowl perfectly. After I am done, I pour bleach on it and scrub it with the toilet brush.
I would think that the harder the stones are, the older they are.
Have no shame...you are amongst fellow flushers !!