At about the same time Joe Morgan-Payler posted this thread outlining some of his experiences of doing just that while working at a Japanese bonsai nursery. viewtopic.php?f=7&t=1307&hilit=stock+grow
I started striking long, thin cuttings instead of the usual 10cm pieces to speed up the process.
My initial trials had reasonably gentle bends and certainly produced far better results than unwired stock but Joe was adamant that these junipers should have lots of really tight bends to give real character as the trunks developed so I rewired and twisted some of them even further. These trees are frustratingly slow to thicken but the original ones are now 9 years old and have reached the stage where I'm starting to do some styling on a few while others are left to grow even thicker.
On Saturday our club had Joe up to lead a workshop so I thought it appropriate to take in one of the really contorted junipers he had encouraged me to grow.
The before shot is not very clear but you may be able to make out a couple of the trunk bends, some long sacrifice branches that have encouraged the trunk to thicken and some of the jins where other sacrifice branches have previously been removed. Please excuse the colour - the flash washed out much of the natural colour and my amateur attempts to rectify it have not really improved it

Remaining live branches were wired and bent to give foliage in appropriate places and to create a crown.
Finally Joe ordered some small shari on the prominent bends saying that these would serve to attract attention and highlight those bends.
The tree is still very raw. I anticipate it ill take 2-3 more years for the foliage to gain density before it looks really good. The shari will be widened and extended every year or 2 until the individual areas join up to give one or more stripes of dead wood winding up the contorted trunk.
Developing shari over time like this gives a final result with more character and texture as subsequent new layers of sapwood are laid down by the tree and progressively uncovered by removing more bark year after year.
Thanks Joe for a great day of bonsai.