Help me unravel this mystery before I burn the contents of this room down

He washed clothes with tissues in and the fluff is from where he’s shaken the tissue out of the clothing?
As for the foot smell, he’s sewn a smelly sock in the curtain seam 🤣

Nosyoldcow, that sounds amazing, do you get purple feet?
My shoes never came indoors without the shoe spray but the house never smelled of death feet so I think it must work. My housemates were very, very blunt so I imagine no one wouod have felt shy of telling me I smelled like a drain.

Slightly off topic, but an old fashioned cure for stinky feet is to soak them in a solution of potassium permanganate. Stains your feet, but they do stop stinking. It must kill the bacteria or infection that's causing the stink. What you do about stuff your feet have stunk up though, I do not know.

Im way too invested in this now so following in hope you get some answers as it sounds waaaay beyond my level of cleaning ability 😬

This sounds like foot fungus. I've had previous dealings with this but only in shoes. Strangley when I worked in a lab my feet had a tendency to smell like supurating death as well.
There's an anti fungal shoe spray I got from ? Superdrug that works really well - like death feet one day and back in the land of the living the next day.

What type of lab did he work in? Hopefully not Porton Down.

I second spraying with cheap vodka. Add a couple of drops of tea tree oil too.

Haven’t RTFT cos it’s quite vomit inducing even thinking about the smell as described but I’d suggest since you’ve already tried enzyme cleaner, maybe spraying cheap vodka out of a spray bottle into the headboard, mattress (any colour-fast soft furnishings basically) as it smashes bacteria. If you mist gently it might be okay on an armchair (test the back first). If all else fails you might want to redecorate? We bought a flat from a couple who had two incontinent indoor cats and only decorating and weeks of airing really beat it.

I think I would have to move.

Buy an ozone machine. You will need to run it a few times and completely seal the bedroom door and start away a few days ( from the bedroom ) but works in any smell as it kills all living things from bacteria to fungos

Not sure vinegar actually kills spores though, especially diluted
And bagging them will just trap moisture in and create a humid environment.

Has a mouse made a nest in the mattress? Could be causing the fluff as it goes in and out?

Biological Aerial powder and bicarb sprinkled liberally everywhere, leave for a day and vacuum. Windows open too.

Bizarrely I was thinking of this maple sugar thing as I was reading your posts. If he has this, I don't he can help it or do anything about. I read a Patricia Cornwell Kay Scarpetta book where the murderer had this some years ago, but I've always remembered it.

Is there anything/anywhere where something could have been hidden to rot and smell, on purpose.

you say he was lovely , etc etc, you did mention his feet etc etc, but maybe just maybe you seriously upset him and he’s secreted something like fish etc somewhere you wouldn’t think to look, like in the story I read the other day of the women who put prawns in the curtain rails of the home her ex husband forced her to leave.

He and his new woman couldn’t stand the stench, couldn’t find it either, so decided to sell up, she purchased the stinky house and he apparently stripped it of everything including the stinky curtain rails.

so slightly off on a tangent but maybe you need to force up a loose floorboard or two. Hope you sort it soon 💐💐💐💐

If it’s a fungus I’d perhaps get in touch with the university to ask if they can identify it/if anything has escaped from their labs… only half joking!

I wonder if he has put a body under the floorboards?

Sorry, but I don't think this is anything to do with him. I would totally strip the room. Do you have a garden? If so I'd wait for a dry day and take everything outside. Then see if the room still smells.

Well that's something, I guess!!

Good luck with this, I'm sensitive to smells so I'm really hoping you get to the bottom of it for your own sanity!

Scientific research, you say...and now some sort of fluffy stuff around the room.

You aren't suddenly feeling an urge to climb to the highest point of a branch and look up, are you?

I've played The Last of Us and this is how you get yourself a zombie apocalypse, you know.

ETA: we had the stinkiest lodger in all of lodgerdom. All bedding was binned, drawers opened, the door shut and the windows opened 24/7 for a fortnight to get the stench out - it was a hard floor thank fuck and it still took that long for the air in the room to be completely changed. Filthy bitch left stuff underneath the bed, including pizza boxes with what might have been pizza still in them. She'd even left a stereo behind and that stunk of her, too. I also had to take the shower drain cover off and unblock it of grey sludge that I don't even want to think about what it consisted of. Two solid weeks of wind, rain, howling gales and a bit of Spring sunshine did the trick, though.

OK, so do you think the lodger has been dick enough to unclip something to put something smelly inside without you noticing?

Bottom on the blind
Curtain rail
Light fixture
The bed frame
The actual mattress