Gemara: Abaye and Rava both say: Any practice that is effective medically does not fall under the prohibition of following the ways of the Emorites.
Ein Ayah: The differences that exist between nations can be broken up into two categories.
One is that each nation has certain tendencies in its practices, which leave an imprint on all elements of their national life. All their customs, manners, and philosophies can be connected to these national characteristics.
There are matters that are within the profile of one nation and not another. Therefore, there are practices that are beneficial for one nation, yet can be destructive for another nation. That is why it is important for each nation to remain true to its character and be careful to follow its own lifestyle. They should not let in too many foreign practices, which could be damaging.
While this is true for all nations, it is even more incumbent upon the Jewish people to be careful about incorporating the practices of other nations. This is because their internal character is bestowed upon them from the experience of accepting the divine light. All of the ways of life that are fitting for them, based on all the aspirations and spiritual visions relating to Hashem, the world, humanity, and society, are unique to them in a special way. This phenomenon cannot be found in any other nation. In general, the practices of other nations are contradictory to such innate aspirations.
On the other hand, there are many matters that might find expression in each nation in a different form, but in a way that is not connected to the character of that particular nation. In that case, a specific nation may have merited, for whatever reason, to discover something that is valuable for all of humanity. Then, there is a way to do this broadly valuable thing with a general characteristic, even though it looks slightly different in different nations.
In such a case, since the need for the practice transcends nations, as it is needed by all, and the reason it was revealed has to do with all of humanity, it should not be limited to the nation which discovered it but is for all. All the nations would be wise to adopt such a practice. In that way, the nations of the world can enrich one another from their valuable cultural possessions.
This is true even if the good idea came from a spiritually debased nation (e.g., the Emorites), which is very different from the nation that needs to adopt the practice in question. The Jewish people should adopt good ideas from other nations, and when it enters our way of life, since it is fit for everyone, it can be effectively included in the nation that has as a holy characteristic.
It is for this reason that whatever is effective medically does not fall under the prohibition of following the ways of the Emorites.