Richard, neither have I. It was the promise of no need for churning that made me try this, and I was very pleased that it worked.
If you want to have a go

there are various very similar recipes, but the one I used makes a little over 1.5 litres (about 2 and 3/4 pints). In a big bowl (bigger than you think you'll need - I didn't and got liberally splattered with cream drops) mix 600ml whipping cream and one tin condensed milk (the sweet stuff) plus 2 tsp vanilla extract (more if you want it really vanilla-y) and a pinch of salt, and if you like 2 tbsp liqueur (apparently the alcohol helps with the texture). Another recipe which I haven't tried yet has 500ml cream and 150g full-fat cream cheese instead of the 600ml cream; I'll let you know if there's any difference when I make the next batch!
Anyway, using an electric whisk (you can do it by hand but it takes much longer) whisk until you get soft peaks (about 5 or 6 minutes). Spoon it into a freezer-proof container and layer it with a flavouring if you like, I used lemon curd but you could use salted caramel or seedless raspberry jam or whatever! Freeze for 5 to 6 hours and enjoy
