Instructables
Picture of Light through the bottle.
This is a picture of a PET bottle, filled with water and bleach: 15  Fl Oz of water and 1.5 Fl Oz of bleach.
1/3 of bottle outside. The bottle then will omit light through the bottle which then makes the bottom 2/3 of the bottle shine a light like a light bulb. I attached a few pictures for you to see an example of the light going through the bottle.