Having several run ins with the :"LAW" I will say that you should never trust the police !
They will lie if they think they can get away with it and it will cost you dearly to get whatever they take back..
So regardless of if ownership of 'drug paraphernalia' is legal or not , regardless of whether you have used the bong or not, maybe you,just purchased it because it looked cool and you thought a friend would like it, the police will swear in a court of law that it was recently used and has illegal substances in it. The police are little more than alternative revenue collection device and ANY reason to seize property or fine someone is all too often taken by the police.
Even IF it is perfectly legal to own a bong and smoke marijuana where you live DO NOT UNDER ANY CIRCUMSTANCE TRUST THE POLICE in that matter ! NEVER EVER !
IN the USA it is best to error on the side of caution lest you loose thousands of dollars in lawyer and court costs ((you will be charged for court cost even if proven innocent) and months or years of angst
The American judicial system is of by and for the rich and meant to drain money from you one way or another. Only the rich benefit in the American just us system.
Now if you have a lawyer on call 24/7 that is to say you have a lawyer on retainer , and you are willing to burn money to annoy the American just us *(justice) system then it does not matter because as OJ proved ,with enough money you can get away with murder. He is only in jail now because he ran out of money.