Zoysia is a slow Spring greener.

Zoysia is one of the turf types that is prone to developing thatch, especially if subjected to improper care. Because of the nature of the plant material that constitutes thatch, mechanical processes need to be employed to remove it. Do you have thatch problem? Remove a 4-6" deep wedge of turf and observe the cross-section. Google "thatch images" to familiarize yourself with what it looks like. More than 1/2" is a problem. 1/4" is not.

Shampoo will not "loosen" or aerify (if that is what you mean by "loosen") soil. It is a surfactant which will result in greater water penetration. The water and soap act as a lubricant allowing the soil particles to move easier against one another.

I'll take a core sample 4-6" deep and post the pic. Thanks for the clarification on the shampoo

Shampoo will not "loosen" or aerify (if that is what you mean by
"loosen") soil. It is a surfactant which will result in greater water
penetration. The water and soap act as a lubricant allowing the soil
particles to move easier against one another.

Normal soil is loosened by the population of beneficial fungi in the soil. They grow to be huge creatures sending out hyphae (arms and legs) all over. Did you ever see a bag of moldy bread suddenly become full of green fuzz? The fuzz is hyphae. That same thing happens in the soil if you have the right conditions. When the fungi are moist they swell and push the soil particles apart at
the microscopic level. When they are dry they shrink allowing air into the
soil and opening pores that will allow future rain/irrigation to
penetrate the soil. I believe the shampoo helps to create the proper moisture levels for the proper time to grow the beneficial fungi. I'm not a microbiologist, but this explanation make sense to me. It makes sense especially because before I switched to surfactant I had success with moisture control on the ground to soften the soil. Surfactant works practically overnight while my watering method took all season. By the way the soil should only be soft when it is moist. When it dries out it will be hard again.

When the fungi are moist they swell and push the soil particles apart at
the microscopic level. When they are dry they shrink allowing air into the
soil and opening pores that will allow future rain/irrigation to
penetrate the soil.

I'm generally aware of the theory of how micro and macro aggregates are formed and the part fungi, proteins, gums and bacteria play in the process and the symbiotic relationship between soil biology and plant, but can you cite the basis for the bolded statement?

I'm unaware of any study that has shown the addition of a surfactant improves microbiological (fungi, etc.) growth and/or attendant soil aggregation. Nor have I seen any conclusions that it would be superior to whatever other methods might be employed in improving soil tilth.

The only surfactant studies I've seen involve their use in cases of hydrophobic soil surfaces.

Aerification is just what it sounds like, adding air. A surfactant reduces water surface tension and allows water to penetrate into spaces that the surface tension would otherwise prevent. Water also can act as a lubricant. Charlatans have been packaging and selling it as "liquid aerifier" for decades. As proof of the product's effectiveness, they challenge the user to insert a shovel (or other object) into the soil before and after use and to notice how easy it becomes after using the "liquid aerifier." The reason it becomes easier is due to the addition of the water lubricant. No air was ever introduce through the process.

I have two concerns with the use of a surfactant.

My first concern is that as plant roots require air, a surfactant will allow water to enter the smallest of soil spaces that would normally hold air resulting in an actual loss of soil air content.

Secondly, surfactants impair osmosis, the process employed by cells to move water and the nutrients it carries throughout lifeforms. My concern is to what extent this may actually damage plant (and micro-organism) health.