I washed some of my MIL’s polarfleece throws that had been sitting on the couch and getting very stinky. Dog smell and other nasty things, plus lots of residue from drier sheets, they felt “waxy” or “soapy”.
I washed them probably a grand total of six times.
I thought they were good after the first couple with vinegar (just fill up the beach dispenser) and one with baking soda, (about a quarter cup) and then tumble drying them. NOT. I took them out of the plastic bag I’d put them in and unfolded them and the smell just slapped me in the face.
So - I washed them about three more times, and LINE DRIED them, outside in the bright sun and the breeze. Took about three days of that serious airing (that’d be wash, line dry, wash, line dry etc) and even my SIL said they smelled like . . . nothing.
I was able to salvage quite a bit of her bedding by washing about three times and line drying, including all her pillows but one. That one was so impregnated with whatever it was (hairdressing? hairspray residue?) that it had hard lumps and I said enough.
I did a lot of investigation including researching how Febreze works in the hope it might help - but Febreze bonds to scent molecules and will wash out so what’s the point. Good luck and I hope you’re somewhere sunny and warm.