Why does my throat get red after using my mouthwash?

Irritation: The mouth wash may have an ingredient that causes irritation to your tissue, you maybe rinsing for a prolonged time. If the redness doesn't go away have and evaluation with your dentist or physician

Allergy: It is very common to be allergic to mouthwash and toothpaste. Try another type of mouthwash. Even if you're in a hurry, using mouthwash is never a replacement for brushing and flossing. Good luck.