How do you remove a spot left by the stain eraser on Uggs? ?

I bought a suede/nubuck stain eraser and brush for my uggs. There was a small water mark on one and I tried to use the ';eraser';, but it seemed to leave a greasy mark. I tried the brush, but that seemed to have little effect. Help!How do you remove a spot left by the stain eraser on Uggs? ?
I'm not sure if stain erasers are suposed to remove water marks. I have a stain eraser and brush from the walking company, it works fine. I would suggest taking they to where you bought the stain eraser and ask them what to do. I would also suggest getting ugg water and stain repellant and spraying your uggs so that your uggs won't get damaged. They sell them at places that sell uggs for around $7 - $10.