My IC has an on/off valve at the input (that I added). I connect the input hose and turn on the water, but nothing goes through the chiller until I open that valve at the input connection.
For the output, I run a 10' hose to the driveway which I secure with a brick to make sure the runoff is directed away from the brewing area.
Drop the chiller in for sanitation with 10 mins left, at zero I turn off the burner, open the valve on the chiller input connection and I'm chilling. If I have a WP hop addition, I can easily shut the chiller water off right there to hold at a certain temp, then turn back on when the steep is complete.
Lately, based on comments here, I have experimented with saving off some of the runoff for cleaning. That works out very well.
IC's are so easy to use, I can't figure out why anyone who isn't doing large batches (where ICs are less optimal) would use anything else. Why futz with cleaning/clogging/not knowing what the inside looks like on a plate or counterflow chiller for a 5 or even 10 gallon batch?