(Not a euphemism!)
We have an open fire in the living room. Last had it swept in December 2020. Only used it 10 - 15 times since then. We can’t get the chimney swept until late January due to us being disorganised and availability. Would it be very dangerous to use the chimney a few times over Christmas? It’s hard to tell how serious this would be online as we use our chimney so rarely.