Yes, Kasenite was a great product, and I loved using that, but unfortunately it is NO longer manufactured. There are other products out there to case-harden, such as Cherry Red, but they do not include the cyanide process that was present in Kasenite. However, Kasenite and Cherry Red do not produce any visible color-case-harding effects.
Case-hardening itself is not rocket science, almost any carbon bearing compound can be introduced to begin the heat process, albeit with varying success. Charcoal (both bone and wood varieties), coal, graphite, and even plain sugar has been used. Turner Kirkland of DGW used to publish the old-time method of packing your frizzen (coated with bone charcoal) inside of clay, placing the clay in a tin can, and baking it in a hardwood fire for an hour or more, followed by quick quenching in a bucket of water. YMMV
At my stage of life, I wilI just pay the money for a commercial product and git-er-done the quick way!
BBG