They probably just cut a really big hole on the top of the skull and slipped a store-bought bong through it, bypassing any need to make any part of the skull air or water-tight, so it would still look cool.

Makes better sense than all that hard work and time it would take to follow the directions the explainer provided.

The funny part is that you can explain how to make a BOMB on the internet but his need to dance around how to make a Bong comes from fear of legal ramifications.

What a country.