Quality Solvay washing soda, which dissolves easily in water, is not enough to dissolve greasy dirt and dust in textile fibers. It is also an excellent companion in cleaning.
It can be used on its own for washing, but to keep the fabric soft, use a vinegar rinse aid.
It washes nicely and you can mix washing powder out of it: 2 parts washing soda + 1 part baking soda + half part active oxy and half part soap grate into a bucket and shake.
You can use it as a scouring powder, you can also perfume it with essential oil.
Do not clean marble, more sensitive tiles.