Scrubbing Bubbles Drop-Ins provide continuous odor protection for a continuous clean. Drop one toilet cleaning disc into your tank to help remove bowl stains caused by hard water, minerals and limescale with every flush for up to 4 weeks. Enjoy the quick and hassle free clean of this automatic toilet bowl cleaner! Have peace of mind with this toilet freshener as the bowl water is not harmful to children or pets, however, it is not recommended that pets regularly drink toilet water.