I would also strongly advise against using the "pillow" I have a number of them from shipments, but they are not like Boveda or HF,,, it is a one way humidification product,,, great for short term use, but not good for a humidor or coolidor.
Any plastic container that has even a decent seal can easily get over humidified, unlike wood containers that can absorb a little extra humidity, in a plastic container it is your sticks that will absorb the extra humidity.
Strongly advise you get some type of 2 way system... do searches on Boveda, Heartfelt or Kitty litter,,,, there are thousands of threads that will give you all the info you are looking for.