Both myself and cincyreefer replied to your question a couple days ago about this, both of us agreed that is isn't extremely difficult to train a dwarf.
I've had two, trained them both, no problems.
1. Feed live food for five days (both mine got 3-4 fresh guppy feeders a day, not good for their nutrition, but starts the process)
2. No food for a week, at all.
3. Then I tried with krill. Used a feeding stick to get the food close to them and move a little in front of them. They ate krill off the stick for a day or two.
4. Third day of feeding I put the krill at the top of the tank, dangled it in the water until they saw it, then let it go and they attacked it. And forever since, I just toss a couple krill in and they nail it on the way down. (I also have a powerhead blowing right at the surface level so the krill moves a lot on the way down)
I haven't had an issue with either one, except one was lost due to an ich/popeye bout.
a big tip: Ask the pet store if it is eating before you get it. I asked them if my guys were feeding yet, and watched them feed them live guppies to make sure. I've heard more people having problems getting them to start eating. Weening them off live food is easier than getting them to start eating in the first place in an aquarium setting. So ask the LFS before you buy them and you should have no trouble.
But here is what kind of lions they carry at the pet store,please help me here.They have:
