It seems that your students do not respond to your well-intentioned teaching methods too positively. If so, the reason for this may be sought in the fact that the Korean cultural background of your students. This background consists mainly of learning by heart and memorizing, and they may not be used to the techniques you are using.

I suggest that at this stage you try to combine the two techniques by partly have them learning by heart and memorizing and on top of that then use your techniques to make them practice what they have learnt before. You should give them handouts or a textbook they can use to learn. Once you realise they do better, and the response is more positive, you could gradually reduce amount of memorizing "activities" by using your own preferred techniques. You may also need to teach some formal grammar, at least the basic patterns.

If all this is to no avail, then you should discuss the problem with other experienced teachers in your place. You should also ask your students if they can understand basic English.

Good luck!