When I make up batches of Evaporation gimmicks I do it in batches of typically at least a dozen.
When I make them I also leak test each bottle to make sure they have working seals. Sometimes in shipping the seal will get damaged, this has only happened a handful of time. This is more likely when you order your Evaporation from a magic shop and there are other heavy items in the box with it and the post office/UPS/ FedEx is practicing juggling with your box. If that happens give me a call or shoot me an email and we’ll get it sorted out for you.