Dear Victoria, I had this with a resident whose health was poor and everything had got too much for them. I visited and empathised with their situation and offered to have the flat cleaned by a professional. They agreed to this and we sent in a firm well used to filth. However, once the flat was clean the resident was able to keep it so. I suspect your resident is in a similar situation. Depending on your finances the Charity could pick up the costs(as we did as it was Ā£700) or add a service charge to her wmc maybe.
Kind regards,
Clare