If it just a Coco block then it should have no salt in it whatsoever
Have you googled the product/manufacturer?
The stuff I get in the UK is sold online by firms who seem to support the hemp growing industry
- you just add water, and it fluffs up to about 10ltrs - last time I bought some it was about £1 a block and I still have about 60 blocks in the shed
If I am using it for seed growing, I tend to mix it 50/50 with cat litter or 50/50 with perlite or 50/50 with vermiculite
Depends on what you are trying to germinate - it's good stuff - clean and weed free