The pipetting-dispensing device (12) comprises at least one tubular pipetting-dispensing needle (14). The method comprises at least one step for rinsing the pipetting-dispensing device (12) using a detergent product, said product being injected into an upstream end (18) of the needle (14) and dispensed from said needle (14) by a downstream end (20). The method further comprises the following steps: pipetting a mucolytic product through the downstream end (20) of the needle (14) dispensing said mucolytic product through said downstream end (20), pipetting a disinfectant product through the downstream end (20) of the needle (14), and dispensing said disinfectant product through said downstream end (20).
