Also known as Huey La / 花啦
Please note that I am listing these products on behalf of my neighbouring stall, hence I may not be able to answer all your questions!
For online delivery, if we leave it all alive with no ice, some will open up and die by the time we reach you, leaving a bad odour. Those that remain closed after being exposed in heat are the dangerous ones that are no longer fresh, hence while they are alive we pack them with ice to preserve their freshness.
You need to soak them in cold water for 30 mins to an hour to clean out the sand first.