White Glass Flask Made in Germany Mouthwash Bottle? Unknown Use

Description

I have cleaned this flask twice but it could use it again. On the bottom it says Bottle Made in Germany. I have seen similar bottles that had been used for mouthwash, so I am uncertain of its original intent. Thank you for taking the time to look.
Condition - I am a Grandmother of seven, living in an Adult Community and am taking my small business online for the first time. I find my items through various routes. Although I make great effort to describe each piece very accurately, it is possible that I miss something, especially on vintage pieces. Pieces may need to be wiped down or polished. Please view all the pictures.
Do to the outrageous cost of shipping, I do not charge any handling fees.
Please note: Whenever possible, I try to use recycled packing material.