Well, I used to have a small bottle of the oil which was once sold by a well known Byron based company, but around a year or so ago I didn't think it was worth having around for the reasons outlined. I used to use it in a head lice treatment I made as I found it worked better than the commercial preparations. But now the kids are grown and lice is no longer a problem I didn't see that I had any need for it. A friend who has a rather impressive array of essential oils took it off my hand to add to her collection.
Just a point on sassafras sold in certain shops; most sass available through these outlets is in-fact what's known as "Chinese Sassafras", probably made locally from camphor laurel. Due to the black market value of safrole, it's also quite likely that what's available contains little safrole as it can easily be distilled off, a little added back to the remaining terpenes etc and sold on as pure sassafras. It only takes a drop or two of safrole to give it's typical aroma. My perfumer friend has a big bottle of sassafras oil but says he never uses it as the odour is too dominating.
Unlike the genuine oil in the bottle I mentioned above, I also once purchased a few OTC bottles (25mls) for use in my Uni project. These typically contained ~17% safrole as opposed to the 85% or so typically found in sassafras oil. In estimating how much is in an OTC sassafras oil, a well known method for safrole isolation is via a freezing process (see rhodium@erowid for details). It might be an easier technique than distilling, although the exercise would definitely be sus in the eyes of the law, so I certainly don't recommend or encourage doing it.
If the cops found sassafras and PiHKAL, IMO they probably could charge you but in all likelihood, if it were only a small bottle or two, I'd suspect their case would be weak at best. Then again, 100mls of 80% safrole containing oil can produce a theoretical max yield of ~113 g of MDMA HCl i.e. over 1,000 doses.
However, if the cops also found MDMA, other illicits or chem equipment, then they might have a stronger case, or least cause for suspecting you were intending to manufacture. I could be wrong here, but there has been the odd case mentioned on B/L, where people have been busted for ordering the oil, despite them having nothing else other than a recipe. Personally, I wouldn't take the risk of possessing the oil if I didn't have a demonstratable, and acceptable (legal) use for the stuff.