• Fuse and temper the crushed glass,
• Compare the washed versus unwashed, and float versus cast,
• Polish the resulting slugs,
• Drop test.

I ran the crushed and washed blown glass, and the unwashed, de-silvered float glass through the following profile in the kiln:

Blown:

Float:

It seems that washing through a sieve is probably a good idea to remove all the very fine glass and any contamination.

• Polish the resulting slugs,
• Drop test,
• Wash both types of glass,
• Use the same amount of glass in the same container,
• Experiment with fluxes.