If necessary, you go full circle by 3D-printing the parts that will be exposed to the liquid out of PLA (or ABS or PETG), which can handle limonene.

Amazon will sell it to you in 55-gallon drums (that’s >200 litres) if you’re willing to pay. That’ll fill plenty of super soakers. So it depends on how serious you are about your anti-robot-uprising prep.

I wonder if you could use HIPS instead of PVA. Still dissolves, but in limonene rather than water, so inadvertant exposure on a rainy day wouldn’t ruin your circuit board. At the same time, the metal should still be recoverable unless there’s some chemical reaction between gallium and citrus oil that I don’t know about.