In 1999 three friends and I descended from the Schalfkogel to the Martin Busch hütte. When we got to the tongue of the big Shalfferner it was not possible to leave the glacier on the southside (the left bank) because there was a wall of ice about 45 degrees steep with falling rocks every few seconds. Because of this we left the glacier on the north side. This was without problems except for the fact that we had to cross the Schalfbach in order tot get to the hut. The Schalfbach isn't a small river though, it is a meter deep and you could hear rocks being swept away in the water. We had to spend a night in the open so we could cross the stream in the morning when it was less deep!
In conclusion, if the conditions aren't much different then we found them I would advice against this route, especially in descent. Ofcourse in a year with a lot of snow getting to the south bank of the glacier is a lesser problem. I also do not know what 2003 did to this glacier, so maybe the problem is gone by now.