Okay so I am a little sensitive to smells but I noticed that if I don't empty my washing machine straight away my washing starts to hustle. At first it would take a day or so before it would need re washing but then this week if I'm not waiting to pull it out as soon as it finishes it hums a bit. So I googled and did boil washes with essential oils, vinegar and soda crystals and it improved a little bit .....briefly......so the next advice was to clear out the filter but the turny bit was broken so I had to use pliers to try and encourage it open but they just broke more of it off so now it is locked shut and broken. I'm desperate so I rang the machine repairer who is going to try and squeeze me in tomorrow. Any bets on what animal has died inside the machine? Has anyone found something revolting causing the smells? Should I just give up and get a new one?
also look at the route the (usually grey) convoluted waste hose takes. If it attaches to the waste pipe from the sink, it must rise up in a loop, usually attached to the underside of the worktop, so that the top of the loop is higher than the water level in the sink when it is full. Otherwise dirty water, tea-leaves, bacon fat and fish-heads can run down the hose into the washer.
if, in future, you take the filter out quite often, it will probably not get stuck again. Ask the repairman if it would help to smear silicone grease on the thread. It is clear and colourless, you get it from plumbers merchants.
Washing soda is more use for removing machine machine sludge. Vinegar will help with limescale, but that is probably not causing the smell.