For my project I started off thinking I would try it with oils, which is my usual medium.  I just couldn't get enough paint on my brush to cover the large areas required with a single brushstroke.  So my 30 strokes turned into many more when I had to keep going back to my palette for more paint.  

So, full disclosure, did not complete with 30 strokes and I lost count.  That said, I really enjoyed painting this.