i just steam clean the carpet over and over and over and over.
(thi brings up the recent memory of the FUCKING IDIOTS AT MY GMAS HOUSE that let their dogs use their "old" room as the potty place, the floor was wood and when we pulled the carpet there was a black spot about 2 1/2 feet wide of rotten wood)
yeah, but anyway, steam clean it once, do it again right after, then i go back the next day after it dries and do it again.
and again
and again.
if its bad it prolly wont work.
;D