Sanitizer soaked cloth for yeast starter?

I am planning to make a Kolsch tomorrow. I just made a 2L starter. I am using WLP029. I have seen on different forums people debate whether you should use foil or a foam stopper. I do not have a 2000 ml flask. I am using something similar to a 1 gallon pickle jar. I was wondering would a sanitized piece of cloth with a rubber band work just as well as a foam stopper.

I am trying it out right now. So if this is not a good idea I will change it. I think this should work, it’s soaked in sanitizer and it is a tightly knit piece of cloth.
Any thoughts or suggestion welcomed. :?:

It should work, so will sanitized foil. I’ve used foil for years with no issues.

I like foil because when cold crashing, I put a rubberband around it and have a good seal.

Thanx. I will continue to use the cloth. If I do cold crash I will probably change to foil. I did some research and there is a site for a group of organic brewers who proposed the use of boiled organic cloth over your starter.

Just FYI - foil is sanitary off the roll. Unless you have gnats, we’re really only worried about things that can fall into the wort and some of those things will fall through most, if not all, cloths but won’t penetrate foil.