I too did my 3rd flush recently. I did get stones, but not as many as before and not as large. However, the Epsom Salts worked too quickly, and as I was taking my olive oil/juice mix, I had my first flush of diarrhoea. This meant I was not able to lie down immediately after drinking the oil mix, so I wondered if it wouldn't work as well as before.
According to some postings though, it seems our lack of stones at this stage isn't really a problem. One person got the biggest stones on his 18th flush! Oh happy anticipation!