The State Coat of Arms of Ukraine. In accordance with the Constitution, the Major State Coat of Arms of Ukraine is to be established with the Minor State Coat of Arms of Ukraine and the Coat of Arms of the Cossack Army of Zaporizhia taken into account as its chief elements.
1 One method is to place three cups of vinegar into the toilet bowl and scrub the stains with a toilet brush.  Bleach Bleach is a very strong cleaning agent. Place a half a cup of dry bleach powder into the toilet bowl and let it sit there for a couple of hours.
Step 4 - Scrubbing. Scrub stubborn stains off of the caulk with an old toothbrush. Try to do this gently or you might actually scrub the caulk off. Rinse the bleach and water solution off the caulk with warm water. If you're not happy with the results, try repeating the above process.