I've just noticed something with the Pico Squeeze...
Using a thick juice like 85-90VG and up, whether using the included plastic squonk bottle or the Luxotic silicone bottle, after the squonk bottle, gets down to 50% full, there is a lot of resistance to the juice making it up the tube and into the deck of the atty.
This persists whether using the Wasp Nano, Nudge 22 or Druga 22.
Mixing a batch of thinner juice like 70% VG solves this problem and the juice flows more easily, and stays that way until there is barely a drop left inside the bottle.
So, methinks that the diameter of the metal squonk tube is likely restricting the flow due to the viscosity of thicker juice.
I had a similar issue when I first started mixing and trying to pull VG-based nic concentrate into a syringe with a 20g needle (blunt tip) and it just would not flow well via vaccuum suction, but a 14g needle (wider dia than 20g) worked much better, but still had lots of flow resistance.
Maybe a similar thing is happening here?
For now my problem is solved by mixing a lower-viscosity juice for squonking, which also lets it wick faster once it comes into the deck, before the excess gets sucked back.