I really don't acclimate fish that I buy from the fish store. I do a fresh water dip with a couple drops of methylene blue to kill off any parasites on the fish before I introduce them in my tank. It is really very stressful for the fish on the contrary but if the fish survives the fresh water dip, it is a healthy fish.
Here is what I do. I fill a small bucket with about 1/2 to 1 gal of RODI water, put two drops of methylene blue in it. Use a heater to raise the temp to the same temp as the DT. I put the fish in the bucket for 5-8 min and observe the fish closely the whole time. Initially the fish will react funny because of the fresh water but will settle down but breathes heavily. If the fish shows any king of erratic behavior or turns stiff, I pull it out right away. Most fish will be fine for 5-8 min. After the dip, I put the fish in the DT. That's it.