Firstly, the research is pretty weak.
Based on 2 people out of 83 users catching covid, vs 10 out of 160 who "chose not to use the spray".
This sounds impressive until you consider what factors made 160 people CHOOSE not to use the spray?
NB - no clinical trial operates in this slip-shod way - people do not CHOOSE whether or not to use a product - they don't know whether or not they are using it as half would be given a dummy spray.
I would expect people who chose not to use the spray to be less concerned about catching covid, and more likely to take risks in their exposure - perhaps younger crowd??
In short, this is most likely to be pure snake oil.