Yes, water agitation and filtration....just obviously remove the filter cartridge if you're going to treat with any medication since the carbon within the cartridge will most likely contain carbon. This is why I have two separate systems, one QT (to observe) and one Hospital (to medicate).
Also, it's good to put a couple PVC pieces, elbows, etc. in the QT for the fish to seek shelter in.
For corals, I do just dip them (for all non-acros) but for a acros I try to always buy from trusted sources or individuals. Then I'll inspect, remove the base of the coral and dip as well.