Office Staff Expected to clean toilets??

Hello,

We're moving offices in March/April and the directors had a meeting about it yesterday.

They told me and another 1 other man in the office there will be a cleaning rota for the men's toilets with just us 2 on it.

There are 10 men that work in this office (only 3 full time) 1 is a director and hasn't included himself in the rota, the others come and go as they work on building sites etc (also not on the rota)

Do you think it's acceptable to ask us to clean after 10 men. Or even to clean a toilet at all?