Bubbles Carry The Departed Off Into The Sunset

Using surfactants, the surface tension of the mixture is reduced enabling a bubble to form. When air is blown into the soap solution, it gets trapped by the surfactant-laden water film, creating a bubble. The soap molecules align themselves at the air-water interface, with their hydrophobic (water-repelling) tails pointing inward towards the air and their hydrophilic (water-attracting) heads pointing outward towards the water. They'd be filled with warm air and the cremains are incorporated into these, through mixture with the liquid, being contained within the bubble or both.

When the machine that does this is turned on, hundreds of thousands of iridescent bubbles carrying the remains of the loved one are carried off by the breeze, filling the sky and blowing away into the sunset.

I like the idea of little sparkly bubbles, but you could also to massive bubbles as well. The link gives a sort of "soul departing" effect.