So my father in laws house has this horrible smell. While my husband stayed there it permeated all his clothing. I have washed his clothes 4 times now including the soak setting each time, the detergent, and a cup of baking soda and they still smell awful. What do I do?!?!?!
I was going to suggest baking soda, but I see you’ve already done that. I’m not the king of domestication, so I don’t know what else you can do. 
Ok. Thanks for trying.
Was your father in law a smoker? Or did he keep his windows shut all the time?
Hopefully it’s not mold that’s causing the smells.
He wasn’t a smoker. Yes, his house was closed up. It doesn’t smell like mold, but the smell is so bad you can smell it even when the front door is closed and you’re standing on the porch @Montezuma
Wow. I’m a little stumped to be honest.

Ah yes, old people smell. My mother-in-law’s house reeks too. They keep it warm, too, which makes it worse. We’re going to tear down the house when she passes.
It’s so awful! We plan to clean his house and sell it. But we’ll need to get rid of the smell first. I can’t imagine how. Ugh!
I’ve heard Downy Unstoppables have a very strong scent but some people have written they don’t like using it.
Maybe I’ll try that. Thanks!
You’re welcome
Good luck!!
I’ve found that once that smell has permeated everything there’s nothing that can be done. Especially with carpet flooring. My MIL’s house is over 100 years old and has been through a fire. It’s wrecked. There is also junk everywhere. I digress…
Have you tried color safe bleach?
That may work.
But honestly,
I don’t know if there’s any hope for clothes that have been washed four times and still smell.
Persimmon soap neutralizes nonenal, the old people smell. Look into it!
Ok. I’ll check it out.
Is it possible to just let them hang outside after another wash for several days?

Ammonia. I get rid of cat pee smell with it. You’ll need to use at least a cup for each laundry load, maybe 2 times. It’s cheap at Dollar Geberal, $1 a big bottle.
bleach will do it
I’m going to try that and then washing with other recommendations after airing them. I have to go shopping to get some stuff
Worth a try. Thanks @anon4362788