What you are doing is fine.
The usual drip method is to start an air tube siphoning into a container with the new livestock. Then use an air control valve or tie a knot to reduce the flow to a slow drip. However, this method is not very good in my opinion. With that low flow rate the water will cool in the tube and container to room temp so you get a slow acclimation to chemistry, but not temperature.
I prefer a modified version that uses a bucket and air tube but instead of slowly dripping the air tube has full flow through it. It goes faster and prevents all the water from cooling to room temp, but it is so little water at a time that it is still a very effective acclimation.
Every fishkeeper has their own method and every type of livestock needs a different level of acclimation. There are fish and even corals that can simply be put in without any acclimation. Other fish and corals can need much longer and very careful acclimations.
