Using rubbing alcohol to create watercolor textures is actually an old resist technique. It works on the principle that alcohol and water repel each other, causing strange and unpredictable textures to emerge. You can create variety in your alcohol textures by choosing one of several application techniques.
For example, you can spray the alcohol through a spray bottle or atomizer onto your wet painting. Or, you can try pouring the alcohol onto the freshly painted surface and tilting the paper to control the direction the alcohol runs. You can also try brushing on alcohol or dipping the brush handle into alcohol and drawing lines into the wet paint.