Review of 8 oz Chubby Gorilla Aviator CR Container:

These will hold liquid but they're mainly childproof airtight containers with a tamper evident seal. Really well made imo.
For opening it has a nice diamond textured grip, and the rubber floating seal makes it pretty much airtight or liquid-proof. It is PET material so they're not COMPLETELY smell proof but for keeping humidity & smells out (or in) they do a really good job. Also they're opaque.