Hi
@Bill I don't know yet.I'm leaving it in the airing cupboard until I next need it!
I generally wouldn't wash thread with any expectation except that you'll have a fun experiment tbh. 😂
This is black so it wont look grimy, polyester so it won't absorb water, and it's thick strong thread so it didnt go fluffy in the wash. But it could maybe still smell rank because of the milky coffee if I didn't get it all out, so I will have to wait and see!
But if you think about how washing is generally hard on fabric, I would expect washing reels of thread would in many cases make the tightly woven reel a bit loose and displaced, and the friction may make fluffy thread fluffier.
I am messy by nature and have quite a few old reels that are worse for wear. I try to use them up on projects where they won't be seen, or use for tacking or craft purposes.
For dust ingrained in anything I put a sock over the end of the vacuum cleaner nozzle to prevent things shooting up the pipe, and use as much suction as the item will tolerate without being too pulled about by the force.
For freshening up stale things I stab holes in the lid of a small plastic container from the recycling bag, fill it with bicarb to make a small air freshener and then bag up the air freshener and stale item, so the bicarb can absorb any moisture and odours without getting white powder onto the item.