I’m over 44 years working for USPS never heard of a clerk confiscating a parcel due to liquid. Hazardous liquid maybe. I’m not even sure they’ll confiscate a kilo of weed if they do they’d keep it for themselves. So I sent a question to a friend of mine that handles that stuff. Here’s the answer.
Non hazardous- ( anything that won’t ignite ) … hopefully not bio hazardous either - if smelly — be sure wrapped well/ double- non breakable container.. packed well.. don’t want anything to leak cause suspicion… when asked “ liquid , fragile, perishable, potentially hazardous, perfume , lithium battery, or mercury? You say yes - liquid- then they ask what kind ? So parcel should be given fragile sticker… and non hazardous.@