Blender pen

Hello to you all.

I need some tutorial help....

I bought watercolors pencils , markers and blender pen. I'm sitting infront my lap with all the tutorials about using the blender pen but....I can't understand!

Can someone explain to me how to use it with the watercolor pencils? 

How I can clean the tip between the different colors? 

Any help will be usuful.

Thanks 

Orit