I sure as hell would not have airsoft parts smuggled in ANY way into the country, specially NOT in work-related containers.
Not only can you get the stuff seized, and the container of (I guess) important parts seized too, but you're in for a lot of legal hell. I'd also choose between getting an airsoft gun part and having a job.
Customs has seized, and searched, stranger things before. Machinery packages and containers are scanned because it is a favorite smuggling method.
Your choice, but man...