What fabric, rope, yarn will work best for wicking water into a plant pot?

I am inserting a 12-inch, bottom drainage plastic pot into a 24-inch tall patio urn with no drainage hole. I want to wick water from the urn into the plastic pot, which I will fill with soilless mix, a standard geranium, three ivy geraniums, and 3 asparagus fern. The urn will sit in sun most of the day.

What fabric, rope, yarn will work best for wicking water into a plant pot?
I have used cotton/polyester rope in the past with success. The poly prevents too much water from wicking up and making the soil soggy.
Reply:anything made from natural fiber such as cotton or hemp
Reply:I have used the old clotheline rope made from cotton. Actual wicks for kerosene lamps work well also.