Removing fiberglass from brass

I got a bunch of fuses from a cleanup job on Tuesday. They are brass on the ends with a fiberglass body. Some have sand inside the body the others I haven't dug into yet, but I think they have a wire running through them.

Anyway I read from Google that 99% denatured alcohol will breakdown the fiberglass. So far I just cut the ends off with a sawzall.

Two questions;

1. Anyone out there know a better/best way to get rid of the fiberglass? (Outside of burning)

The sand inside also contains little pieces of what I am hoping is silver. The little pieces are about the size of an unused staple (about the size rectangle & thickness). Theses are big industrial fuses like 2 feet long. I tried the "poor mans silver test" that I learned from reading gustavis's posts here on SMF. That is rubbing them on a piece of white paper and they do leave a mark on the paper. However, I rubbed a known silver bar (Wall Street mint) on a piece of paper and that left a mark as well, so I'm a little confused if that poor man's test works or not.



2. Anyone know if these chunks in the sand are indeed silver? I'm scared of chemicals BTW lol.

Silver Recycling

Don't know if this helps, I have no sound on this computer, but it was the first thing everyone's friend google came up with...