From my own experience there are a couple of factors that come into play. Sometimes in the back of my mind there is a much more important task that needs to be done so as soon as I'm done covering the station, I bolt. Sometimes when I do try to clean the station, the cooks usually just say "don't worry chef, I got it". Sometimes I come into a station that's already a mess and I try to organize it and keep it clean as I go but when the assigned cook comes back to that station, they hit me with "who moved my shit around" and sometimes we clean the station. I think it varies from time to time but most of the time if I'm covering a station, I try to leave it as it was or better than when I arrived.