For the liquid, you could use the Wiggle 2 addon on a simple armature attached to a boolean cutter to fake the sloshing. Here’s a quick test with this setup I did a while ago:
2024-01-26 08-43-12.mkv (3.5 MB)
FLASK_wiggle2.blend (177.7 KB)
This Blend file probably needs the addon installed to work but after that it’s possible to bake the motion.