When I was getting beer on the month club deliveries, it came ups. Each bottle had a cardboard package and six bottles fit into a box tightly. I would assume ups knew that it was beer because they would have picked it up from the beer club or the brewer. Also, my mother gets wine delivered ups. And I sure they know its wine. It come direct from the winery.
The rules for FedEx and UPS shipping for businesses is different than for consumers. There is (or, was when I last looked it up) a process for obtaining approval for shipping alcohol commercially.
Whether it's legal to ship alcohol in the US is complicated. The rules are different for each state, and in states where it's legal, it may be different depending on who's shipping it, who's receiving it, etc. Plus there may be tax requirements. To make matters worse, the rules change frequently---for example, Indiana has repeatedly changed its laws in the last few years as they (happily) keep getting struck down.
If the shipper is the USPS, the rule is simple, though. It is against the law. (
https://www.usps.com/ship/can-you-ship-it.htm) Don't do this.
If you're shipping with UPS/FedEx, it's up to you to determine whether it's legal between the states in question. If it is, then the only issue is with the shipper's policy. They may refuse the shipment, dispose of it, or send it back to you (not sure how they handle it), and it's possible you'd wind up on the hook for something if your bottles leaked and damaged someone else's package, but there aren't legal issues there.
There's no reason to play cutesy games like "yeast samples" or the like. You do not have to disclose the contents, and as others have said, it's not going to fool anyone. Certainly it's not going to make anything that was illegal become magically legal. If you're going to deceive the shipper in order to get them to accept a package, you might as well go whole hog and come up with something that's less likely to arouse suspicion---it won't be any
more fraudulent.