Chullin 16: Blades and Invalid Slaughter

Today's daf speaks to other methods of slaughter that are not permitted.  The rabbis focus on blades that are attached to water, or wheels, etc.  Further, if a handle is removed and replaced, there is a question as to the validity of the slaughter.  Interestingly the rabbis discuss the reed, a sharp, dry grass, which is not permitted because it might leave shards of itself in the offering.  For that same reason it is not permitted to use a reed for other purposes, including for wiping oneself after defecating.