10-Undecenoic acid (Undecylenic acid) and the salt forms, which include calcium undecylenate, sodium undecylenate, and potassium undecylenate, behave very differently in the body.
The salt forms (calcium, sodium, potassium) require an acidic environment and therefore have very limited potential in the body. Their effectiveness is primarily limited to the stomach. Many people however, have low levels of HCL due to fungal candida, so the salt forms may even be less effective.
10-undecnoic acid in the oil form does not have the limitations of the salt form and has a very broad application throughout the body. Thorne Research is one of the main producers of this product under the brand name, SF722. When they ran out of it a couple of years ago due to supply and contamination issues, they tried to get practitioners to switch to their Undecyn product, which contains the salt form combined with HCL. This was a disaster for practitioners as the effect was not the same. Adding HCL to the formula did nothing for its effectiveness.
There is no comparison between SF722 and Undecyn in their effectiveness and there has never been. SF722 is Thorne's #1 selling product and they lost a lot of money during the 5+ months that they were without it.