Just make sure to clean out the tank, but one thing I have been told. "A healthy fish will not let itself starve." So I wouldn't worry that much they will eat when they are ready!
Mine really enjoy Fluval Bug Bites. They will also eat frozen bloodworms every couple of days when the frogs get them. I have never tried freeze dried ones, but maybe soaking them for a min so they sink would help? They are mid feeders mainly. It really only took a time or two of thawed bloodworms sinking past their school to figure out they are tasty. Now they will go down and steal from the frogs if they can.
Think the issue is they float and neons are midwaterfeeders. Soak them befote you feed.
I found that not only do freezedried bloodworms float but as they sink they look like fish poop. So I chop mine up in a little dish and soak it in fresh garlic put through my garlic press. (all fish go crazy for garlic) Then it looks like what they know food to look like and they are drawn to it by the smell.
I take the frozen bloodworms and thaw them out in a cup for like 15 minutes, then feed them to my neons and they go crazy over it. I give all my fish bloodworms 3x a week as a snack.
Bab Dat Fish
Don’t you need to soak the bloodworms in water first?
Also you could use as he/she suggested the bug bites
You can add frozen blood worms right into the tank, or you can put them in a cup with tank water until they defrost