Well after having some very badly neglect azaleas myself that were as
tall as my house and taller, I just knew I had to do somehting with
them so I could get sunlight back in my house and see out of the
windows. I cut them way back to well below bottom of the window
heights, and other than not having as many or no blooms the next year
they came out great. They are nicer and much fuller now. IMHO its
pretty hard to kill a well established azalea by pruning. Their old
and new wood is full of buds that will push out and give new stems
when wood or limbs are cut off. The pruning will stimulate them to
erupt and start new.

I had gone by the 1/3 rule but soon found on azaleas its virtually
impossible to harm them and other than having scragly looking plants
for a period of time they will do fine.
Visit my website: http://www.frugalmachinist.com
Opinions expressed are those of my wifes,
I had no input whatsoever.
Remove "nospam" from email addy.