What tests are available to detect C. Botulinum/Botulinum Toxin in fermented meats?

I am interested in the preparation of fermented dry-sausages (salamis, summer-sausages, etc) where due to the humid anaerobic atmosphere inside the salami. It is a good environment for C.Botulinum spores to grow.

The mainstream food safety practice is to use Sodium/Potassium Nitrate or Nitrate + Nitrite, which are suspected carcinogens.

I would like to prepare fermented dry-sausages without Nitrate usage and test the finished product after for the presence of C.Botulinum?

Salamis are usually 10-50cm, and if I were to consume or sell them it is viable for me to test each salami. Thus, I am also interested in the viability of taking a few cuts out of a salami to test for C.Botulinum presence, would a small cut on the sausage be sufficient, or it might be that there is a growth of C.Botulinum in a small part of the sausage not throughout the whole sausage making testing a sample not likely to reveal whether or not other parts of the sausage have C.Botulinum.

Also concerned about whether lack of C.Botulinum is sufficient proof that the salami is clear, or whether the bacteria might have died off after producing the toxin. The same concern about whether if there is toxin production should it be throughout the salami or in isolated pockets making testing a small sample from a large salami not viable.

Based on this situation what would be a test that is will allow me to detect whether a salami is likely to cause botulism?

Is it as simple as some gram stain and an optical microscope?