This may be the first time I’ll followed yahoo answers for advice. Not that I entirely followed it. I forgot the ½ tsp vanilla and used regular salt. Added berries.
into 1 pint-sized plastic zip bag (sandwich ziplock):
2 Tbsp sugar
1 cup whipping cream
two handfuls of frozen strawberries, chopped in food processer
into 1 gallon-sized plastic zip bag (frozen pasta bag)
3 ice cube trays of ice broken small in food processer
6 Tbsp salt
Put the zipped sandwich bag into the bigger one and shake for 5-7 minutes.