Things you can make using a bleach bottle
Clean out thoroughly then cut with knife or scissors

Store or mix other chemicals
Funnel
Bowl to hold CLR or other chemical while cleaning sinks etc
Mixing Bowl
Mixing bowl for drywall compound
Paint bucket
Storage container for old sponges
Diffuser for light
Mold for shoe goo or concrete
Place behind outlet cover to hide hole or imperfection
Tool box liner