UltraDEXDaily Oral Rinse With Fluoride 500ml

How long does this last for, if used twice a day?

Would this still work if I used it say, once a week?

Will this help clean the bottom of my tongue because I can feel (like there’s gunk there) , I’m always cleaning my teeth but still have bad breath

After how long after rinsing my mouth with this product in the morning can I start eating or drinking?