We do EOTs thats not really unusual, the wall will mostly clean up pretty easily with nothing but a wipe although skirting needs some decorative work(we would normally do the wall as well unless the landlords a tightwad.), I have seen new buildings get in that state in 12 months all it takes is lot of condensation, no ventilation(they actually block up vents now for fire standards in HMOs) and some furniture in the wrong place. More interested in what you used to clean the carpet chem wise.