I'm not sure what manual you are reading, but normal flora in a birds mouth, is gram positive. So is it, in humans. Gram negative in humans, is in the colon. Feces contamination. It IS important, to keep birds out of your mouth, and not clean your teeth, as they like to do so. I also feel it is important to accept the regurg. They work hard to offer it to you. They are showing love. I wait all the time for Sophie's regurg. Sometimes it takes her 10 minutes to produce. I wait patiently. She offers me her regurg in my hand, I pretend to eat it, thank her like crazy. She is pleased.Regurg, is a form of affection, and I have NEVER dismissed it. It is a present to me, and I thank her everytime. You can train your bird to regurg in your hand. nancy