Godlike knows the secret, follow these instructions and you will do well.
The most importtant part is changing the papertowles and keeping refrigerated.
Also if you are out on the coastal beaches bring home some sea water tofreeze these little jewels in, this is the only way to preserve them, works great in emergency situations but dontt expect them to be like fresh.
Also Dennis company in Aberdeen sells a special shrimp gun that sucks these babys right out. made of smaller pvc but twice as fast as clam guns.
Thank You.