What kind of smell? Mold, dead animal, old smoking, what?

not really sure what it is. Might be a combination of all of the above. There was definitely signs of rodent droppings in the house.

Oh boy. If someone left out poison for rats, and it was not the kind that dries them up into mummies which do not stink, then you may have a dead animal smell.

I'd also recommend that you check out any sewage connection which may be beneath the mobile home. They might have had a crack in the plumbing and some seepage dried in the insulation.

Then again, do you know what a skunk smells like? That odor lingers a long time if it sprayed on the premises.

I'm just going down the list of things that I know can smell pretty bad. Include mold on that list too.
Good luck getting rid of the smell.

You mentioned using vinegar before, but you can get better results with the vinegar if you do this:

Put it in a pan diluted by half with water. Add some cinnamon and some cloves. Then let it simmer and simmer for a long time inside your mobile home. I've used this as an odor eliminator for years, having used it to remove the smell of diesel fuel from commercial boats, to remove fish cooking smell in any place, to get out the smell of smoking from a house, and I recommend it as a way to get RELIEF until you find the cause of your problem It smells like apple pie.

It won't remove the mold and mildew itself, just the smell. If you wash the walls and the a/c ductwork with it, that might help. Be sure to change out all your a/c filters and your range hood filter.

>If someone left out poison for rats, and it was not the kind that dries them up into mummies which do not stink, then you may have a dead animal smell.

Yes, but at least it will go away eventually, if that is what it is.
In addition to what moccasinlanding suggested, I would also look up underneath the house. I've known people to have raccoons/armadillos/younameit eat out the bottom housing around where pipes and such enter and make nests in the insulation down there.

BambRose, if it is flooded under your house in the crawl space, it very well could be mold.

You asked if the dehumidifier would take away the one inch of water in the basement, and I don't think it will, but then I'm not a person who ever lived with a problem basement. There is a Basement Forum where some of the folks might be knowledgeable on this.

Do you have a mobile home, or a manufactured home?
Is it permanently fixed above a dug out crawl space? How high is the crawl space? Has it ever flooded before to your knowledge, or since you purchased it?

Can you also turn on a couple of box fans to move air through the space? Ventilation can help dry it out, but if it is a paved crawl space you are dealing with, it won't be draining into the soil.

Good luck.