Bloo Blue Water Original In-Cistern Blocks Twin Bloo Original in-cistern produces a lasting, clear foam with every flush, leaving your toilet sparkling clean for longer. With Bloo Original in-cistern you can get up to 8 weeks of freshness (each block lasts up to 4 weeks) There is no need to unwrap the in-cistern block as this will dissolve in the water. Expert in Fragrance Cleaning Bloo products help protect and freshen your toilet so that it shines! From rimblocks to in cistern, Bloo’s fragrance-full aromas help make your loo the Best Seat in the House Bloo Original in-cistern produces a thick, clear foam with every flush, leaving your toilet sparkling clean for longer. With Bloo Original in-cistern you can get up to 8 weeks of freshness (each block lasts up to 4 weeks) There is no need to unwrap the in-cistern block as this will dissolve in the water.