Re: Why don't we practice chokes?
"Grabbing a neck" brings forward the imagery of someone reaching out and clasping my neck with both hands. This, to me, is an invitation for broken elbows unless the person reaching out is VERY strong.
Properly done "shime waza" with or without clothing involved requires a lot more control of the person than reaching out to hold onto the neck. If you have that much control that you can actually do the shime-waza, then you should also have the control to recognize when the person is "out" (should be within a few seconds) and it should be safe to disengage and get some distance between you and the person - they SHOULD wake up unless you've gone way past the "reasonable force" situation and held the choke on for a minute or three...
Frankly, I hope I'm never in a situation where I need to use this outside of the dojo..