I know Cantos Espirituales have been used in Cajon Pa Los Muertos.
Nolan Warden had done a lot of excellent research on this musical style/relegious activity.
Mr. Warden's thesis is available here:
http://www.nolanwarden.com/Warden-CajonPaLosMuertos.pdf Some clips of the "ceremonial" music are available here:
http://www.nolanwarden.com/grupocueroycajon/index.htmlI'm with you thought, those Cantos Espirituales are beautiful and I have tried to throw them into rumbas, etc...