Help removing smell from stone fireplace

Especially the directions about removing people and pets and plants

Asking for my own educational benefit- won’t an ozone machine just clean the air in the room? What about the source of the smell?

It will break down any voc and other organic compounds. It works like bleach but for odors by oxidizing and breaking down the cause of the odors. It usually attacks the strongest odors first just because they are the most reactive (and hence the reason they are the strong odors). It will also penetrate into any porous surfaces when high enough concentration and long enough treatment.

Gas insert? Maybe someone retro fitted gas into an old wood burner that has begun to fail.

Stone and mortar can absorb odors and staining. Wash liberally with TSP and maybe spray it with a good Enzyme cleaner like Eco Strong. Leave to dry. Mask off floor. Have you cleaned the chimney? You should. Home has been primed and painted? Cleaned or replaced blinds and drapes? Cleaned windows and screens, changed hvac filter?

So, you already cleaned with TSP and used enzyme cleaner? I'm curious which you used.

Definitely try an ozone machine! If you have a neighborhood FB page, maybe see if one of your new neighbors will let you borrow one? Just be careful while using it and make sure to follow directions closely

I’ve never done this, but I wonder if renting a commercial grade ozone machine would work. Like something they’d use in a hotel room.

I would not use any king of paint. I’d rent a high pressure steam cleaner like a Ladybug. You can also use it on tile, walls, windows, tub/showers, lights, and some flooring. It doesn’t require cleaning products and should remove a lot of bad smells as well as kill dust mites that can contribute.

Try drowning it in a product called odoban In theory it should work. You might have to do a few applications but the product is cheap

Ozone generator. Either large one for full room or build a temporary wall around it with plastic and treat just that with a smaller unit. No persons or pets in home while treating. Air out fully before letting people and pets back in. Everything else you could do would be temporary at best. Even sealing or painting (which I wouldn't ever do) will still just be temporary and still have an odor.

Wood burning ? Get it cleaned, the chimney… all of it

Why does it smell like death?

Mix white vinegar and water 1:1 in a spray bottle, saturate the stone and grout, let it sit 10 minutes, then scrub with a stiff brush — vinegar breaks down the tar residue causing the smell, not just masks it. For stubborn spots, a paste of baking soda and water left on overnight works even better since it actually pulls residue out of the porous stone instead of just wiping the surface. Rinse with a damp cloth after either one. If it's still lingering after a couple rounds of that, the smoke's probably gotten into the fireplace flue and chimney too, not just the visible stone — worth a chimney sweep to check, since that's often the part people forget and the actual source of it "seeping" when doors are closed.

Stone and grout don't absorb cigarette smoke, that's not how this works. Would recommend burning a creosote log to clean stack. If that doesn't clear it up, have a chimney sweep out to the house. Washing drywall with TSP might be required. May then need to paint with an odor blocking oil based primer

You can cut off its nose but you will spite its face.