Soaking the shells in bleach will help you clean them thoroughly. Scrubbing them would also help get rid of the sand and other particles that may stick to the shell. Once done, you would have a clean shell worthy of the custom’s scrutiny. You know the risks of bringing shells into the country. Despite you knowing about it, you would want to give it a try. Besides, customs may be forgiving and allow you to bring the shell back. Or this shell may be harmless, and so you decided to bring it back home. If you are bringing a shell back from another country, you need to declare it with customs. Not doing so would result in a penalty of $300 and a lot more. And so, it is best to declare. But before bringing it back to the US, you have to ensure you have a clean shell with you. To be honest, the people at customs wouldn’t want to even look at dirty shells. If you don’t clean them well before presenting them to customs, chances are they will say no. There is also another reason why you need to clean them well. This is also for you to rid the shell of bacteria and other foreign microorganisms. We are not saying the microorganisms are dangerous. But we know that they belong somewhere else in Cancun, where you took the shells. Exposing these microorganisms to some other environment may have unknown reactions. We don’t know how they will react. And that’s something we don’t want to risk. And so, there is a need to clean them up. Customs will always decline dirty shells. This is because dirty shells may pose a health risk to the citizens. To clean your shells, you only need to follow these simple steps. – In a tub, pour in a solution of 1-part water and 1-part bleach. – Soak the shells in the solution for about an hour. – Once done with soaking, remove the shells from the water-bleach solution. Scrub the shells with a toothbrush. – To clean the shells well, use dish soap when brushing. This should get all the dirt and sand out of the shell. This should also be an effective way to rid the shells of microorganisms that may still stick. – Rewash the shells. – Put the shells on top of a towel or some napkins. Let the shells air dry. – Place them in a clear container. You can also use a clear bag in keeping your shells. Using a clear container or a clear bag will enable customs to see the shells easily. Again, the US government does not have anything bad against shells. The thing is, they need to keep everyone safe. The shells need further evaluation. This is before they are actually allowed entry into the country.