IIRC the Staedtler Mars Plastic is good and readily available. However if you are trying to rub out small details (which you might be on a music score) you will soon rub off all four (or eight) sharp corners and then it'll be a problem.
You can buy things that look like propelling pencils (which sometimes accept the refills which fit in electric erasers) and these allow detailed erasing almost regardless of the state of wear of the refill. You might like to consider one of those.
The pentel clic eraser ZE22
is like this and IIRC the refill material is very similar material to the Staedtler eraser.
cheers