Naughty Thomas has decided the corner of the room is a great place to urinate

it's in the exact spot that a large cabinet was last week but we've moved it to do get the room painted - obviously Thomas does not like furniture changes!
Anyway the room stinks to high heaven and I wonder if someone could recommend something to neutralise the odour? I have tried washing the carpet in washing up liquid/water solution, have tried carpet cleaner and left the window open all day but to no avail - it still stinks.
Am I imagining it or does dusting the area with bicarbonate of soda help?