Odor Under House Coming into House

[terpgirl30]

I have had a number of feral cats making a home around me. The weather in MD has been horrible recently, and they (and a raccoon) are under the house regularly.
I noticed odd odor a few years back that came and went. It's extremely erratic, and I think it follows weather. Initially, I thought it was my cats, but I couldn't find anything. It's not my cats.
NOthing is coming through vents. I've tracked a major source to under the jacuzzi. There are doors/cabinets surround the jacuzzi. If you open this, you get the smell. You see the underbelly of the jacuzzi and see a pipe going down through the floor. That seems to be a major source.

I'm thinking under the bathroom cabinet is a mild issue, too...again, there is a pipe with something cut out. That seems to be letting odor up.

First I want to know if anyone has dealt with this. I feel like I'm going crazy here. I can't find any info on it.

This is a two pronged question
---the weather is ridiculously horrible in MD now, so there is no getting under the house anytime soon. I can clean under there in spring, but I've seen one post about this elsewhere (and that's all I could find). It talked about boarding up the underneath so nothing can get in. That's not realistic because of how the deck is set up. What would be my steps here?

---inside I'm looking at an air cleaner, higher grade about 600 that says it deals with urine and uses activated charcoal as well. I'm unemployed right now, so this is a hardship, but I'm not sure what to do. My family doesn't think this would but the cleaner says money back guarantee. I've thought of putting activated charcoal in containers under the jacuzzi about 30 dollars or maybe a filter or fabric of charcoal under there. Then maybe activated charcoal under the house. Right now I have baking soda under there, and a few bowls of vinegar...lame but a little helpful.

I thought about contacting a company that cleans after an accident figuring they deal with crazy odor. Want to see what they use. Or maybe a rental center to see what people rent for crazy odors.

Thanks in advance.
Kim