How to do make up using brush to draw sprite and remove using shower?

I want to make dress up games in unity. i have done all the part of dress up to wear cloths , earning , hair , lips etc. But how can i apply makeup on the face as you see in the picture.

I want to apply the makeup on the face using brush and i also want to remove makeup from the face when i use the shower.

Makeup you see on the face is just image, i want to draw image on the face where i touch using brush on the face and remove only part of the image where my shower touch the sprite.

can anyone help to do this? or anyone have done this in past?

one approach to do show , whenever you touch the face just increase the opacity of image you want to display . increase slowly by using this line of code
gameObject.GetComponent<Renderer> ().material.color.a=0

and decrease the transparency when showering.Decrease it to zero when it is not visible .
you can also divide the image to different parts then then increase and decrease when touched specific part.
OR you can also use the fill property of Different parts.For draw Effect

If you use sprite approach - consider using “Sprite Mask” (Unity - Manual: Sprite Masks).

If you create you game in Canvas then use “Mask” component (Redirect to... title of new-page).

Both approaches worker well for me in the past.