Baking soda may help with certain odors and light residue, but it should not be treated as a reliable method for removing established mold.
Is citric acid better than vinegar?
Not universally.
Both are acids and can affect certain materials. Bosch, for example, advises against using both vinegar and citric acid in its washing machines.
Should I run the washer at 90°C?
Only if the manufacturer’s instructions or the machine’s cleaning program allows it.
Some machines use dedicated cleaning programs at lower temperatures.
Why does the rubber gasket smell?