Watering with a sprinkler, drip etc has a serious disadvantage , a lot of water gets lost by evaporation . So I always thought of using Olla for irrigation . The idea is that the earthen pot is dug into the earth next to the roots of the plant and water seeps out slowly right next to the roots . And then I had this inspiration what if I replace it with a plastic bottle with tiny little holes . Sadly even the tiniest holes makes the water gush out and in less than 10 minutes all the water is gone . Then it was suggested by the good people at Gardenstew that I should put some cotton yarn in these holes that will act as a wick and regulate the water . So I did exactly that and the system seems to work .Here is a little graphic to explain the idea . Needless to say I used Inkscape for the graphic.
Apparently this idea always existed and wasn't as original as I thought .
Silicon can also be used in conjunction with the cotton yarn to reduce the water oozing out of the holes .