I too am a fan of White Lady, very tasty and stringless, but they do seem a bit more prone to seed rotting than the more traditional purpley-black varieties I used to grow.
Using saved seed from last year, I soaked them in water for half a day, then put them into a sandwich box between two layers of just damp kitchen paper. Roots appeared on all of them in two days, so into paper pots, again, easy on the watering. Mostly all up now (some of them, inevitably it seems, choosing to break out through the side of the pot!)
I also sow some direct when planting the others out - they seem to germinate OK at that stage, and if you can keep the slugs away it does extend the cropping season a little.