It works verry well but test it first on just a few leaves because if you add too much oil you can suffocate somme plants.
Beter do not use oil at all if you dont have aphids or otther insects.The oil is an insect killer and you can use even cooking oil.In order to disolve the oil in the water,you have to mix it first with dishwashing detergent then you can add the water.
The baking soda its a verry good antifungic but also test on a few leaves first ,especially on acid loving plants.
For aphids i use just dishwaser detergent and water ( no oil) and as an antifungic i use diluted Chamomille tea instead of baking soda.