Hi Yager,
The fridge is an excellent method to destress an axolotl (axolotls love the cold) but it is not too helpful when it comes to encourageing an inappetant axolotl to eat as the axolotl's metabolism is slowed right down.
Is there a cool place in the house where you are able to keep the axolotls water temperature below 23C? Water temperatures above 23C will stress the axolotls, leading quickly to illness, and death.
An axolotl will not eat if he or she is stressed.
I would try leaving the food in with the axolotl for a couple of hours, and cover the container with a teatowel or similar (as the dark, cool and secure environment should encourage the axolotl to eat).
If the bloodworm is not working for that axolotl, try finely chopped earthworm (portion sizes should be about as long as the axolotls mouth is wide) or live blackworm.
Those containers look a little small. An icecream container (4 litres) or a bucket will give the axolotls a little more space (they grow quickly) and the increase in water volume will also help dillute the axolotl's wastes more efficiently.
If you cannot keep the temperature within the axolotl's favored range of temperatures (14C - 22C), then the fridge will be the best place for them.
A fridging guide:
http://www.caudata.org/axolotl-sanctuary/Fridging.shtml