I use the Japanese cotton stuff (Koh Gen Do), and I find myself wicking once every day or two days.
It depends heavily on the juices I'm dripping though, like I can use the same wick for about a 3-5 days if I'm dripping only one flavor profile (ie: only tobacco-y flavors, or only fruity flavors). If I'm switching often (which happens more days than not), like going from a fruity juice to a chocolate/tobacco juice, it's necessary to change more often.
Also I've had some wicks work better than others, some of my best have been using a very very small amount of wicking material, and in doing so, I was able to use the wick for a full 12 days (I was on vacation and didn't wanna have to change my wick tbh, so it worked out well), and it tasted fine despite switching juices multiple times a day. I find what really ruins wicks more than anything is ANY sort of dry burning to them. Sometimes I'll have a relatively fresh wick but if I get a gnarly dry hit I'll swap the cotton out, because after that dry burnt hit it'll never taste quite the same.
On that note, I need to rewick today lol.