Don't do it here.

Signs are always an easy way of poking fun at foreigners. By way of apology I have to admit that, were I to try writing a sign in Arabic, I would probably be arrested for blasphemy, treason, libel or numerous offences against calligraphy. So it is with some humility that I have to ask what this sign might mean?

Do not inflate balloons near this building.

This sign might be appropriate placed next to a sluice or some designer toilet bowl, but it was attached to a wall in an otherwise empty subterranean corridor.

Sounds fairly reasonable (subject to not washing the other hand as well), but why would anyone want to...

I suspect this is a euphemism similar to an American's request to 'use the bathroom' - that is to say that our US cousins do not actually want a room which contains a bath. Similarly, this sign has little to do with hand washing (other than it is recommended afterwards).

This pair of signs on the security man's desk are a little less obscure, and even provide a mobile phone number for continuity of service. Some people never go off duty.

The answer to the question above:

Spitting Image

Just as well, really, it would be a full time job.

Tomorrow or whenever: Something else...