You will need:
1/2 liter of hot water

1 glass of white vinegar

1/2 Glass Back Sprayer

What to do:
Bring half a liter of water to the boil and before it starts to boil, add the white vinegar and mix well.

While cooking, stir baking soda into the oven you want to clean.

Remove the vinegar and water mixture from the heat and pour it down the sink to mix with the baking soda in the oven.

There is an immediate bubbling reaction. Try to close the entrance of the pipes with a plug. This will prevent water from falling on it for at least an hour.

Or if possible, leave it on overnight and repeat the trick at least once a week.