Gone are the days when you went shopping and brought home 4-5 different bottles, one for each surface of the house! Now, in the space of half a bathroom drawer, you can have a detergents supply that would make a cleaning company envious.

There are two types of super-concentrated detergents: pods and tablets.

Both have the irresistible advantage of the total absence of water, which enormously reduces their weight and therefore the CO2 emissions related to their transport. Furthermore, being "dry", they do not require a bottle to be contained: we can finally stop buying useless plastic that we use for a month and then throw away.

In the next lines I will try to describe the two types, underlining the pros and cons of each.

POD

These are all those products in which the "active part" is contained in a small balloon made of polyvinyl alcohol, a synthetic polymer used in a wide variety of applications and with the characteristic of being soluble in water but not in organic solvents.
The balloon allows the active part of the detergent dispersed in organic solvents to be contained until it comes into contact with water, at which time it will dissolve, releasing the active ingredients [1, 2].

Tablet

In this case we are essentially talking about compressed powder, which therefore needs almost nothing to stay together. Here the cleaning part of the detergent is in the form of powder which, in contact with water, dissolves and disperses.
A possible disadvantage of this type is that, depending on how the tablets are formulated, they can be slightly crumbly and therefore get a bit damaged during transport. In addition, depending on the ingredients chosen, some components may not be able to dissolve perfectly in cold water, resulting in a higher fixed residue than pods. This is not in general a major issue, except when fixed residue is the enemy, such as with window cleaners.

But do household detergents in pods or tablets clean well?

To this question, the only serious answer I can give you is: it depends on what you need to clean.

Surfactants that are commonly used in detergents formulations have a limited solubility in water and just a fraction of them can dissolve spontaneously. To increase their concentration it's necessary to heat and stir at temperatures and speeds achievable only by industrial processes. This means that the concentration of surfactants within super-concentrated detergents is lower than that in ready-to-use detergents.

Super-concentrated household detergents are therefore not suitable if you need extreme cleaning power, such as for your oven, the BBQ or the fryer. However, if your needs, like mine, are 99.9% of the time limited to cleaning the stove after I've made a steak or ragù, or cleaning the bathroom from limescale and toothpaste splatters, then you won't be disappointed.

[1] Wikipedia, "Polyvinyl alcohol"
[2] Chimicamo, "Polyvinyl alcohol"