The actual origin of the term is from England, and began in the later middle ages. A corpse would be laid out, and a bucket of holy water placed at its feet. Visitors could then sprinkle the deceased with Holy Water. Other explanations (suicide, execution) came later to explain an idiom, of which the origin of the term had ceased, mainly as a result of the English reformation.
"To Kick the Bucket" is explained by Bishop Abbot Horne in 1949, in his booklet "Relics of Popery" Catholic Truth Society. He adds "Many other explanations of this saying have been given by persons who are unaquainted with Catholic Custom"