Zach of course was holding a hosepipe, which I removed using a background shot. Partly by masking off the relatively static length of hose, and the rest using bodged-together chroma-keying of the yellow of the hose.
There’s next to no live sound; only Zach saying ‘I need a pee’. The swishing sound for the last shot was some sound of just spraying at a wall, then I created bass-boosted and treble-boosted versions, and mixed back and forth between them according to roughly what direction Zach was pointing the hose. Turned out OK I think.
OpenShot seemed reasonable enough from the small amount I used it. It did crash once, and the dialogs for editing properties of clips were slow in appearing, but mostly it was perfectly usable.