Device for preventing the clogging of a drainage system

A device for use in a drainage system, the drainage system having a trap with liquid in a low point of the trap and having an opening for access to the low point of the trap, to prevent clogging of the drainage system which comprises:

• (a) a container having porous walls and configured to be positioned in the liquid in the low point in the trap;
• (b) a composition located in the container for inhibiting growth of microorganisms in the drainage system which can clog the drainage system;
• (c) a flexible member connected to the container for removing the container from the drainage system and having a length such as to allow the container to be positioned in the low point of the trap;
• and
• (d) a stop connected to the flexible member and configured not to extend over the opening of the drainage system and to prevent the flexible member from completely entering the drainage system to allow for removal of the container from the drainage system, the stop being configured such as to not interfere with the opening of the drainage system.