Hi Yvo,
You could try making this into a granita. I haven’t done that before with milk, but report back here with your results! For granita, you can omit the gelatin. The gelatin keeps the ice milk from being too icy, but that is the goal for granita!
Anonymous,
There are cooks who use agar agar in place of gelatin. You can look here for more information: In The Cooks Thesaurus
it states that agar agar sets up a little differently, but for this ice milk, I don’t think a little variation one way or another could hurt. Hope that helps!

Hi teno1010,
It sounds like you may need to add more cold water to the gelatin, “blooming” is basically hydrating the gelatin before heating it. If it looks like there are still some dry hard patches, I would add more cold water.
One teaspoon gelatin takes about one tablespoon cold water.
I hope that helps!