It's an old fpv-drone parts thingie for ice and maybe water.

Print two mounts for the bottles, one of them mirrored.

Figure out how differntial thrust and mixes work in BF or iNav. You can do it without an FC too, but with FC it works a lot better and is easier to control.

This is a good link

https://github.com/betaflight/betaflight/blob/master/docs/Mixer.md

But the basic idea is to select "custom" and then set motor one and two like this in iNav and it's something very similar in BF (ok, looked it up, it exactly the same).
mmix 0 1.000 0.000 0.000 -1.000
mmix 1 1.000 0.000 0.000 1.000

Update: I made a new holder for the bottles, it's just bit thicker.

Creality

CR-10

I use PETG, it works very well.