Cleaning out a smelly suitcase

Ok, a dorky question, but I’m out of ideas.
I have a problem with a suitcase: its insides smell and every time I use it my clothes come out horribly stinky. It was not like this when i bought it, so something else must have happened.
I ddin’t put any bottle inside that might have spilled, and there are no stains on it that suggest something else was spilled on it, for example during flights.
I tried keeping it open outside to the fresh air for a few days, and the only result was having the guys upstairs (they share our back yard) complain. I also tried with liberal applications of those sprays that are supposed to freshen up fabrics, but after a few hours the usual stench comes back.
So, is there something else I can try before giving up and buying another one? I’d prefer to avoid that as I’m not exactly rich and that suitcase is quite new - only a couple of years.
This info could be useful: it is not a hard-shelled, Samsonite-like suitcase: it is made of some soft material covered with fabrics.

Vinegar is really good at removing smells. I’ve never tried it on a suitcase before, but if I were trying to get rid of the smell I would soak a towel in vinegar, and seal it up in the suitcase for a few hours. Remove the towel, wipe out and let the suitcase air out and, by all accounts it should be fine.

Charcoal is good for absorbing stinks. Try filling it with charcoal, closing it, and leaving it for a few days. If you can’t get charcoal, burnt toast might work: it’s a good trick for freshening up nasty sneakers, anyway.

Obviously, your suitcase is cursed with an evil, unhappy spirit. I recommend calling an exorcist.

Actually, I recommend trying vinegar. But I’m not sure that you should put the whatever-soaked-in-vinegar in direct contact with the surface of the suitcase. It could end up, I think making your suitcase smell very strongly like vinegar instead.

Baking soda also absorbs odors. Fill a small cloth bag and leave it inside, even when you use the suitcase. Change it out every so often to keep it fresh.
Hey, it works in the refrigerator!

I had the same problem and I was told to put a bunch of balled up newspaper inside the suitcase. It worked quite well. Now, I also store it that way in the closet.