So my disgusting roommates have not been cleaning the bathroom more specifically the toilet despite saying that it would be cleaned at minimum once a month together. So it's been me cleaning it because they will literally let the toilet turn black with grime and not do anything about it.
So I finally brought it up to one of the suitemates and asked what he thought about switching off every other week and he straight up said no I'm not cleaning up after other people (

)
So how should I tell this pig that he needs to clean the toilet without resorting to the RA?