Which are absolutely unnecessary and environmentally unsound.
But apart from this, I've been following the 'If it's yellow let it mellow, if it's brown flush it down' dictum for some years now. (The lid of the toilet is always kept down.) If my wife doesn't use cistern blocks (these things appear intermittently), everything is fine. However, when she puts the blocks in, there is a reaction between the urine in the bowl and the chemicals in the blocks resulting in a crust forming around the sides of the bowl.
This can't just be wiped or brushed away. The best way I've found to get rid of it is to use a (dedicated) pan scrubber. But it's a pain in the arse, to coin a phrase.