Planters, pots or baskets can be lined with “a disposable nappy” to absorb water.
The principle of “no leaks” is obvious but the water is absorbed in the same way a baby’s urine would be.
Just as it is held away from a baby’s skin it is stored in the gel form away from the soil.
Then the moisture is released by transpiration in to the soil directly as the gel warms up during the day.
OBVIOUS NOTE, use a clean Nappy!