Dynamically section off small areas each day to tackle, and it will eventually be cleaned
It would take a good while to break the habit of leaving half-eaten food around, just consider cleaning it a chore to be done near the end of the day
The only way successful cleaning would be impossible, is if one gives up before completion, or declares it too much of a hazard to be cleaned
Keep an attitude of "getting it done" each day, and it will eventually be complete. Simple as.