since I purchased my plate chiller I have used hop sacks. Before that i would just throw them in the boil. So far, i have not noticed any difference as far as the utilization of the hops, but i also have only brewed three times with it.
After I'm finished with it I have been pouring some pbw in thr wort out side and letting it sit for a few minutes. Then I just place it sitting int he sink under the faucet and run hot waster through it for a few minutes. Before using it to chill I then throw it in a bucket of star san for a couple minutes. I also boiled it once after use and think thats overkill. This method has been working good for me so far.