Before jumping to any conclusions about the origins of the word "Zydeco", let me direct you to the following vinyl album, onBellot Records
out of Nigeria--
Prince Thony Adex and his sedico system - Juju funk explosion - Vol. II
LP, M 2386

I have this album--the music is a bit in the vein of King Sunny Ade--Prince Ade is called a "funky juju guitarist", and this music is, in fact juju ritual music--although juju ritual music is a lot like party music--what they call juju, we call voodoo--

The peculiar business about flags and flag boys that comes up in songs like "Iko,Iko" is less peculiar when you know about the Haitian Voodoo Flags --

At any rate, "sideco" is a word that means "ritual" in either Yoruba or Swahili--I looked it up once, and saved the whole dictionary that it was in to one of four hard drives, can't find it now--

Some knows, and some thinks they knows.