... the cello, itself.  I tried out Mike Block's cello/bow at a concert/workshop once, and he uses one.  It makes perfect sense if you do vigorous and care-free strum bowing and chop technique on the C string.  I went through one in a about a year, and I didn't replace it, but this thread reminds me that I really should as a bit of extra protection.

Instrumental playing is based on multiple sensations.  One may hint at them, and induce them on occasion, but ultimately each individual must arrive at these sensations on his own.
Janos Starker