Odour of Faeces in 2023 Mazda CX-30

[MundeDas]

Hello, I need some guidance about a bad thing that happened to my 2023 Mazda CX-30 TPP.
While riding shotgun in the front passenger seat on October 3, 2026, an individual experienced a severe case of diarrhoea in the afternoon. While it seemed like most of the poop stayed in her pants and dress, some seeped through and ended up on the seat cushion and lower back.
The unfortunate passenger sat motionless for nearly three hours before finally getting up and getting herself cleaned up. While driving home, she changed out of her contaminated pants, re-on her dress and remained seated for another hour. Approximately four hours passed while she was in the seat following the incident.
We used Mrs. Meyer's Clean Day Multi-Surface Everyday Cleaner to remove the affected areas the next morning. The cleaning cloth did not show any signs of faeces, but there was still a strong smell.
I drove around with two bags of activated charcoal in the car for a few days, occasionally cracking the windows open. The stench faded with time, but it lingered close to the wounds.
In order to get the inside spotless, I had a mobile detailing service clean it with enzymatic cleaners, steam, shampoo, and ozone on October 6. Though he could clean and extract the upholstery, the detailer said he couldn't dismantle the seat to get to the foam inside.
The interior appears to be spotless as of this morning, October 8th. Nevertheless, a portion of the faeces smell is being concealed by the cleaning agents. In particular, the area where the seatback meets the cushion near the bottom is where I can smell it when I bring my nose close to the seat.
On rare occasions, I can smell the faeces without bringing my nose close to the seat because of the wind blowing through the right side window while I'm driving. Because of this, going about my daily driving is a real pain.
My biggest concern is that the liquid has seeped through the holes in the leather and is now sitting on the foam inside. With the heated seats, passenger occupancy sensors, and side airbags, I'm not sure if calling automotive upholstery shops is the best course of action.
My enquiries are as follows:
Can the smell be totally eradicated without having to replace the seat or its foam?
In order to clean or replace the foam, can an upholstery shop for cars remove the leather covering without damaging the original upholstery?
Which one would you suggest: a local mechanic, a Mazda dealership, or an upholstery specialist for cars?
Does the presence of airbags, heated seats, or passenger occupancy sensors depend on the foam being removed or replaced?
Can I buy just the foam for the passenger seat if it needs replacing, or do I have to get a whole new seat?
Does anyone have any similar experience? How much did it cost and what worked in the end?
You have my utmost gratitude.

[Bedelon]

Requesting a seat from scrapyards would be my next move at this point.

[Starat]

Trade it in 😁

[Ledgerciao]

You could try an ozone generator (which costs $50 on Amazon) and an Oxyclean soak. Oxygen is necessary for decomposing organic matter that you are unable to reach.

[BuffUpdate]

Sure, I would have gotten a new seat right away if I had been in that situation.

[Shiyardit]

If I had been in that situation and intended to retain the car, I would have gone out and bought a new seat right away.