One LFS here does nothing but float the bags the shrimp come in for about 30 minutes and then releases them..if the water in the bags and the tank they are going in are close in sg.....He said he has almost a perfect 0 fatality rate........Another place acclimizes by temp and also drip and also claims the same thing..Both agree shrimp are among the hardest to acclimate and the key is do it slow......
I did mine, buy drawing off some of my tank water after checking SG of tank ......I pour out all but a small amount of original water that fish, shrimp etc is bagged in, and place fish etc in a clear plastic container.......I then add one third of that containers capacity with water from the tank, every 5 or 6 minutes, until I do it a total of three times where I now have doubled the containers contents. Then I pour off 1/2 of this content, and repeat process again, and also one more time, for a total of 9 steps of adding and replacing and pouring off some water over a 45 minute time frame. So far it works fine. I do not know if it makes much difference or not, but I try and do my acclimating during early evening so once fish etc are placed in the main tank they get a few minutes to take a look around and spot a place to hole up, then its lights out.....Next day they get their first feeding.
For corals and snails etc I remove from bag, and place on paper towel for about 1 or 2 minutes to allow them to fully deflate or drainout any original water they held, place in the tank and thats it. When they pump up again they have all my tanks water, and little to no lFS water was introduced.