Lao cha is very expensive, even in Taiwan itself, so why not giving it a try?

Seems also be a recent trend in Taiwan…
So I went to some local markets and found some really nice (presumably) Qing Dynasty porcelain jars. I like sort of wabi-sabi imperfect ware, of which is there are loads and the prices are surprisingly reasonable (got a whole bag full of cups and saucer as well

(Gonna post pictures when I have the time)
Anyways, one is smaller and probably better to be used for short- to midterm improvement of tea. If I am not wrong for this kind of short storage, the original lid without any additioal sealing should suffice, no?
For long-term storage wax sealing seems to be best.
I keep seeing teajars where the lids are either wrapped in cloth or with a cloth squeezed in between. Anyone more knowledgeable got a good idea what is the exact purpose and if it is advisable? I imagine it provides a better air-tighness?
Anyone knows what kind of textile shoul dbe used/avoided?
I would ask my trusted tea shop, but no time in the near future to go down south, so any help is greatly appreciated!