Very interesting. Where i searched: Aleppo soap is classified as a Castile soap as it is a hard soap made from olive oil and lye.
I remember using Castile soap for cleaning engine oil from the cooling system after an oil cooler failure.
Perhaps because it contains lye.
Also found this: Though originally sourced in Syria, most Aleppo soap is now made in Turkey. This is because the war in Syria makes obtaining the soap all but impossible.
I put it on my Amazon wish list, for the skin not the radiator. Thanks