From the TSA

Exceptions to the Restrictions for Liquids, Gels and Aerosols

All prescription drugs and over-the-counter medications including insulin and other diabetes medical supplies, petroleum jelly, K-Y jelly, eye drops, and saline solution.

Liquids including water, juice, or liquid nutrition or gels for passengers with a disability or medical condition.

Life-support and life-sustaining liquids such as bone marrow, blood products, and transplant organs.

Items used to augment the body for medical or cosmetic reasons such as mastectomy products, prosthetic breasts, bras or shells containing gels, saline solution, or other liquids.

Frozen gels or liquids are permitted if required to cool medical and infant/child exemptions. Ice is permitted as long as there is no melted liquid present.

Baby formula, breast milk, juice or water for a traveling infant small child.

Breast milk is in the same category as liquid medications. A mother flying without her child should be able to bring breast milk through the checkpoint, provided it is declared prior to screening.

If you have liquids, aerosols, or gels the meet these exceptions, they can be in containers larger than 3.4 fluid ounces (100 ml), and do not have to be inside of a quart sized plastic bag, but do have to be declared at the security checkpoint.

Have a letter from your doctor for you mouthwash and in my experience you'll be OK. Just be prepared to show off your tongue....