Cool...I will give a try with a sprayer and sponge as the backup.
If there is ANY wind it goes everywhere.
https://www.screwfix.com/p/no-nonsense-poly-backed-dust-sheet-12-x-9/89591 Hang something like this across the top of the posts to rear of the panels. Should soak up overspray and then drip down (at worst).
Oh dear me that's a serious mess, hope your neighbour paid to have it all professionally cleaned.
Don’t bother with a sprayer it runs down and makes a mess. Paint it on for a professional finish.