I'll tell what I did with the 3 cleaners, 1 Blood & 1 peppermint I have......
Put the bag in the tank for 30 mins with it still sealed shut to allow the temp to equalise.
Open bag & hang it off my lid so its still in the water & rig a bit of air tube with air valve on end from a plastic container full of tank water standing on lid, draw water through air tube & slowly close the valve until it drips about 1-2 per sec, put tube into bag & leave like this for 2 hours. you can tie a knot in the air tube to get it to drip but the valves are a lot easier!
you might have to use another bit of airtube to draw some of the water out of the bag every 45mins or so as it gets full, don't put that water back in your tank!!
at the end of 2 hours I slowly tip the bag of water through a fish net into another container until I have the shrimp in the net which is then released straight into the main tank, the water in the containers is then dumped down the drain.
Cheers Shelton.