There are basically two ways to handle this situation with the first one being the do-it-yourself route and the second one being the professional hoarders cleanup; both have where they can fit well:
The do-it-yourself approach: This is a cheap and simple method that will normally work in a situation where simple casual carelessness is the problem. You can simply buy some simply available cleaning products that are available in your regular supermarket even though most of them may not be able to deal with tough stains. You could call up a few friends or relatives to help you out and with some determination, the problem will be solved in a short time.
Hoarding cleanup: Hoarding cleanup, on the other hand, is a daunting task where do-it-yourself will not generally work out. There are serious hoarding conditions where large amounts of filth and debris are found; some hoarders homes have been found with large amounts of trash, fecal matter, urine, expired foods, boxed items, food wrappers, pet droppings, mold and mildew to name a few. A great amount of care needs to be taken in such extreme cases in order to avoid contamination and spread of disease. Cleaning up gross filth, which is known as hoarders’ cleanup, can be a great challenge and it requires trained personnel who will also be able to deal with contamination and odor removal. You will need to pay for professional hoarding cleanup but when you consider the stakes that are involved; whatever amount of money you are going to spend will be relatively small compared to the services you will receive.