Incredible! We have a second-hand flat over who was tip-top renovated, only in the toilet there was deep under (washdown) left and right small deposits of urine stains. For months I've tried it with all possible means. Finally, I wanted to please my husband already to change the toilet. Then I read of Domestos toilet flash and its action to dissolve urine stone and thought to myself, one last attempt you dare. And what can I say? It works even under water ... in an afternoon (exposure) everything was gone and me radiates the shining, literally re-acting to WC. TOP!