To examine my stones during my flushes I bought a wide plastic colander that fits my toilet bowl in width. So, when I do my flushes I just install it there, (the rims of the colander lay on the rims of the bown), and put down the cover. The rest is as usual. It is good to have shower hose (I'm not sure what it is called in English)close to the bowel to be able to wash the stones right on the spot.
The stones are easy to cut because they are mostly like plasticine.