Making washing machine soap

You can make your own washing machine liquid soap

The amounts you'll use will make you laundry soap enough for around 50 loads. This soap doesn't make much bubbles but it cleans spots very well besides it's safe to your washing machine. You simply need 1/2 a cup of sodium borate (Borax), 3 tbsp washing soda (sodium carbonate) and 40g (around 11/2 oz) of a soap bar. Your favorite scent (1 tsp of any essential oil)

Grate soap first and put it in a pot contains 1/2 a litre of water. Heat to melt soap but not to boil. After soap melts, put it in a large plastic container and add 5 liters of warm water and stir. Mix borax and sodium carbonate (washing soda) with the whole solution until they all dissolve. Add the essential oil and stir again. Cover and leave for at least 8 hours. Mix and add to plastic bottles and store for 2 months.

I've tried this recipe and did an experimental load of kitchen towels and the result was marvelous!
I also want to share how I made washing soda. Washing soda is much more expensive than baking soda. You can prepare washing soda starting from baking soda. How?

Line a baking tray with baking paper and flatten using a wooden stick. Bake in a 180^oC (350F) oven for 50-60 minutes.