Mine told me otherwise when I talked to him about problems with thrush.. He said to use water or saline to rinse after steroids instead of mouthwash because listerine kills good as well as bad bacteria.

I just did very quick search and the Asthma and Allergy Foundation of America says: “The good news is you can keep your mouth healthy! After you use your asthma inhaler, rinse your mouth well with water and spit it out or brush your teeth. If you have a child with asthma, they may be more likely to get cavities, so it is important to teach them to rinse and spit after using their asthma inhaler.”

Asthma.net says not to brush for 30 min., but rinse thoroughly. This seems like a reasonable compromise. 😀