Sharing is caring, but there are limitations:

You can share new brushettes. Putting up a box for your household with a bunch of function is typically what is Brushette about.

You should neither share your brushettes, nor the neck adapter. Aside from general hygienic concerns, there’s also a risk of transmitting diseases that are generally transmittable by blood, like Hepatitis C.

You could share your electric toothbrush handle.