Had the experience of flying such a detail about 3 months ago. Was quite moving as the chap tipped his fathers remains out of the DV window of a PA28 with a vicar in the back reading a psalm. He did struggle to get the ashes moving at first stating, 'he always was a stubborn old ******!' All went well until we got a huge dose of blowback and aircraft & occupants were covered in ash! I did feel a little guilty leaving the aircraft with the engineer when we landed telling him it needed hoovering!
It provided a variation from the normal 'how many times did you nearly get killed today?' conversation in the bar that night anyway!