There. Fixed it. You are trying to paint the scenario that Law Enforcement gets to determine illegality. That is inaccurate. What determines illegality, in this case, is the the person who buys the bong articulating his motive to use the bong for drugs.
For example, you could walk into the store, just an ordinary Joe Bloggs, and say "I want to buy a bong to smoke some marijuana." BANG! The law has been broken once the store owner sells it to you on that basis. You intend to use the bong for an illegal purpose.
If you were to go to a fertilizer store and ask to buy some Potassium Chlorate "so that I can make a bomb to blow up a school" the law will similarly have been broken if the store owner sells it to you, knowing you are going to make a bomb with it.
If you were to go to a gun shop and ask to buy some bullets and a gun "so that I can assassinate a head of state" the law will similarly have been broken if the store owner sells them to you, knowing that you intend to murder someone with them.
This is exactly how it should be. If the store owner knows you are going to do something illegal with your purchase, he is culpable if he sells it to you on that basis. That is how the Common Law works.
and yet, after purchasing the bong, joe is not commiting the crime of pocessing drug paraphenalia, no matter what he said to the clerk - until the point if and when it is used for such illegal purposes.
it’s an absurd law that criminalizes the actions of an otherwise normal transaction and targets mainly small independent business owners.
it’s an assault on liberty.