But your argument is self defeating, because placebo can be a highly effective catalyst. ESPECIALLY something that works with the olfactory sense, which is closest to the memory center in the brain's physical layout. As a result, just smelling something can invoke strong emotional and memory responses that arise subconsciously.
Further, reality is the sum of one's perceptions as seen through the lens of one's chosen beliefs. Most things that claim to work on a conscious psychological level fundamentally require a degree of suspension of disbelief in order to be applied as their very nature is of rational logic that must be met with a willing and open mind. Anything that you would jump to call "placebo" responds to the same approach. But one must first be willing to see that their perceptions are a product of their beliefs before such an approach can be deemed rational.
The interesting thing about this given treatment is that it does provide a lot of olfactory stimulation and probably is working directly with the subconscious more prominently than a homeopathic treatment that does not work on the olfactory senses in this way. In this sense I would say this has the potential to work more effectively than other homeopathic treatments, as it does approach the olfactory center, which does have a notorious reputation for direct subconscious communication with the memory center and therefore has the potential for a stronger "psychoactive" effect.