Mix cabbage, carrot, and raisins in a colander. Pour in boiling water and let it run out of the colander into the sink. This will wash the vegetables, but also wilt them a bit. Let all the water drain and let the vegetables cool to room temperature.
2. Season salad
In a large mixing bowl, toss the salad with the mayo, then season with salt to taste.
3. Chill and serve
Chill and keep refrigerated until it's time to serve.