The gel dip may have beneficial stuff added to it. But, the major reason for the gel is to keep the foots moist. Roots going dry are the worst problem to trees.
I dibble the hole open, put the agrifrom tabs in, fill the hole with water, put the plant in. I usually put a small handful of soil right over the roots, Close up the hole wioth the dibble. Then, I play in the mud.... I push the open wound in the ground with my hands, basically seal it up with mud I am making.
I havent used any powders or gels. But, I would save the gel for the package of plants that came out of the bag on the dry side. That's the real survival rate killer there..... The gel works long after the intial watering inside the soil to keep those roots moist.
I do not plant and monster ones...... I put them in pots, shade them a bit, and plant them in the dead spots..... When you watch the ones that dies, see how big they are. The smaller the better.
I dont plant hundreds anymore. I do 75 or 100. IF you dont have the time do it right, the will suffer. I also cut cardboard I have laying around inot 2ft square and use it like landscaping fabric. I go to the store and buy mulch when its on clearance in the fall.
I got a 55 gallon drum with a hose and valve on it. I can drive by the plantings and water them easily during a dry spell.