Ecoline Brush Pens for Flash?

I just ordered a 10 color set of Ecoline watercolor brush pens as I keep seeing such positive reviews & have heard many people praising the paint-load in each pen as well as the fact that they actually contain PAINT as opposed to colored dye..

 

I’m just wondering if anybody has used/uses these specific brush pens to whip up flash?  If so, how do you enjoy them & do you have any pointers/tips for a newcomer with the product?? 

 

Thanks!!