If you add oil to your bath, the oil often lay in lumps here and there ON the water, it don´t mix WITH the water. To fix that problem you need to add cream. Cream takes good care of the oil atoms, and your oil will be well mixed with the water. On the pic I have my beloved avocadooil, Jasmine - and Patschouliessence and some cream. I take 1 (not more) drop jasmine, 4 drops of Patschouli and 2 tablespoons oil to this tiny liqueurglass with cream, stir and pour it in the bathtub while the water is still pouring.