Hi.
Yes it is true that borax will choke out all fleas. Before monthly products like frontline were invented, busineses sprung up all over the country and made a lot of money doing just that.They treated peope carpets with a borax dust.
If you have an animal it is easier to just apply a monthly product. If you have no pets, this is definitely an option.
Please let me know if you still have questions or wish to discuss this further. I am happy to help.
Sincerest best wishes,
Terri
Feline Healthcare Expert
Expert in feline health and behavior. 20 years experience with cats.