Try dipping salwater from your tank out and defrosting your food in the tanksaltwater. Simply dump defrosted food plus water back into your tank.
Now being that there be any number of ways for what one could do in the hobby itself for being that there is so many of us who keep these tanks that there is always many difference in our opinions.
Now what I not can see, in my opinion is where you say in to dump the food and plus the "Water" back into the tank. I would never suggest something as that for OK, I might be somewhat old fashion somewhat, but still that part I cannot understand for you thoughts be the water place the odor of the food for peoples eels, they will not need that kind of help.
Like the water I use to defrost my eels food is filtered water, I not use water straight from the sink.
Then place sealed bag in ziplock container.
Now, I have to admit that is something I never thought of
Have a ziplock bag of food that has only enough for one week of feeding that you are opening regularly. The rest should be sealed in the ziplock and then the container for longterm use without being opened until it needs to be used.
Making bags ready for feedings is something I myself been doing for a long time that a variety (mixer) of foods be in one double ziplocks.
The only one problem I will have is my supply of frozen octopus because I have to buy the whole 24# box that the octopus is in 2# packages for this will last far past even six months for in one 2# package is about 18-22 octopus.
I had offered some people I know who lives near me that they can have some if they needed it.