The "target device" I am using is nothing more than a twig from the same tree I cut down to make perches etc for Polarn, I just took a knife and peeled off the bark to make it look a bit different from his perches... Even a wooden BBQ stick would work.
And about giving up, pleas don't, birds do take their time to adapt. I've been able for some time now (not long tho) to give Polarn treats where he sits but he wouldn't walk for them until yesterday morning. So I started the targettraining yesterday, well I've had him touching the stick to get a treat before, but never walk for it. So yesterday morning I started to really concentrate on the targettraining since he was willing to move for a treat. He was sitting inside the cage then but wasnt willing to move up and down, just along the perch. Later on yesterday he was ontop of the cage and seemed more eager to climb the sides etc to get to it. Today I have been targeting him from the top of the curtains and across the room to the wardrobes down to the bed etc. second training today I targeted him around a bit then laied down on the bed and targeted him onto my tummy, this was the first time he actually stepped on me. I then targeted him to my knee off of me onto the bed and then back etc, the session ended with him sitting on my hand and we kinda worked on getting him comfy with me lifting it up and down. He won't step up on it if I try target him onto it from the cage tho. But half burried down in a pillow so that the arm is all visible but no big hight diff between.pillows and my arm seemed to work ok, and he allowed me to raise it and put it back down, well he flew off a couple of times but then I could just target him back to the bed.
Polarn is still quite young, so I don't want to restrict his food but small prices of dried banana chips seems to get him working
Just wanted to let you know that with hard work and some dedication your buddy's fears are gonna go away. I'm working on my taming as well seeing Polarn is an aviary bird that was raised by his parents, and he has only been here a couple of weeks so far, but then a lot of research, taking every opportunity to learn something seems to help. Oh also I am quite confident that I will not have to catch Polarn again just to make sure he gets to the cage to eat and drink. He now flies back and forth quite frequently. Sometimes to eat or drink, sometimes to play with some toys. But his cage is always open, except that I close it for a couple of minutes every now and then and sometimes a little longer just to make him comfy that it will open again.
Keep working with your friend and you will soon see him getting quite close to you asking for a treat, I've learnt Polarn to shake hand, a no exhausting trick but still a chore to perform in order to get a treat.
Sorry for making the post long but one more thing, before I started the second session today (kinda what kicked off that session was Polarn finding the target stick on the nightstand walking across the bed with it standing behind my chair making a clicking sound holding the stick, so I'm pretty sure he knows what the stick is, and the clicker. So hide your stick if youre not targeting and wanna treat him, I wasn't sure what todo so I clicked treated him, picked up the stick and targeted some. And decided to keep the stick inside a locker, just so that I in the future decide on when to target. Not sure if that was the right descition, but I had to make it on the fly so that's what I did.