Neighbours cats weeing on Astro grass

[Greybutterfly]

Any knowledgable cat people out there ?!?
Our next door neighbours have four cats (2 male - 2 female) that see our garden as an extension of their own. I have no problem with this. However we have paid a lot of money for a new garden including artificial grass and I am worried about the cats peeing on it, ruining it and basically the garden stinking of cat wee.
The idea of the artificial grass was for convenience and I simply can’t be arsed to have to wash it down all the time (and don’t yet have an outdoor tap)
Has anyone got any “cat friendly” cat deterrents tips?

I don't have artificial grass but my neighbours have a dog who wees on it a lot so they just hose it down every so often.

Thanks @firestarterdumdedum ... your neighbours are probably more vigilant than I am lol ... that’s what I’m worried about

Hose it down, lot easier to clean than real grass.