Lotsa
I took a lotta bottles one trip. I wrapped each in bubble wrap with those big bubbles. I also put a piece of bubble wrap at the bottom of each bottle. All held together with masking tape. All survived the flight.
You may want to make the bottles so large that stealing them would be very conspuious. In a bubble wrap, wrapped in clothes (with arms of shirts left free to dangle) all held together with masking tape and twine.
Good Luck (and what a nice thing to do!)
SC