I have this problem. My TP hit its absolute worst just recently. Can't seem to move onto target, my arm feels "stuck" low and left. I know if I release then, it will go low. But I can't smoothly bring it on target, hold, and release like I used to. So I try to "throw" the arrow up and right, which of course results in poor arrow flight and even poorer accuracy.
I went to a shoot couple weeks ago which was beyond embarrassing, it was just plainly sad. I used to shoot half decent, which makes this loss of control and accuracy absolute agony for me. I'm at the point where it's either: (1) cure the TP, or (2) give up archery.
I read Kidwell's book a while ago, and back then, I tried his technique, but sort of half-a$$ed, and I got some, but not much, benefit from it. I'm now committed to using Kidwell's technique every day: morning, noon, and night.
I have 6 weeks in which I must completely cure my TP.
I've already spent a week on the first part, and it has seemed to help. I would suggest randomly moving around, not solely the figure eight. Figure eight isn't bad, but I think the more pattered your movements, the more likely the TP will return, if only in a new form.
I've also used my regular bow a little bit with step one. When you're holding a full-weight bow, there is a lot more temptation to release early. Of course, you can't do it as much, but I find it helps to occasionally use my regular bow.
Also, I found it is necessary to take it outside to the range, and do the drills just as if you are going to shoot, from 20 - 30 yards. For me, there is a night and day difference between doing drills in the living room and actually standing at the stake on the range. During the latter, it's like my brain says "OK, now this is for real," and it wants to go back to all the bad habits.
So, I haven't beat my TP yet. I'm just starting really, seriously working on it. I hate to say it, but the drills in Kidwell's book are boring and tedious. But his explanation of why they work makes perfect sense to me, and also explains why it is necessary to do the drills a lot and often.
Today is the last week of week 1, which was all step one. Tomorrow I'll start mixing in step 2. With any luck, I'll have it licked in 3-4 weeks, and the last 3 weeks will be drills + practice to regain my confidence.
Anyway, that is my plan. Hopefully I'll be posting back with good news and updates in the next couple weeks. All I can say now, is that it does seem to be helping. Do the drills from Kidwell's book, and don't cheat. And do them often and a lot. It doesn't do any good to just sorta do them, every once in a while.