I change nibs constantly because a lot of what I do is try out different vintage nibs, or write letters and I feel like a different nib on this letter, or want to use different paper, or I'm just messing around writing for the sheer fun of writing. As an example, I'm currently working on another nib comparison, this time with 9 different stub nibs. I'm also going to do a re-working of my informal Falcon comparison and I'm up to around a dozen different Falcon nibs. That's a lot of prepped and ready-to-go nibs to just sit in a tin and sort through.
I wipe mine off thoroughly, but don't re-oil them. I've yet to have one rust on me. If I re-oiled them, then I'd have to re-prepare them to use again. I actually try very hard to not get my fingers on the underside of the nib so that I don't have to re-prep a nib before using it again.
I'm actually trying to figure out a good way of keeping all of my prepared nibs that are ready to go, out and stored so that I can easily grab one and write without having to dig through a tin and possibly get my finger oils on it again. I'm thinking something like those magnetic strips you sometimes see for storing knives on a wall, but smaller and on my desk. Maybe some small magnets with an inlaid metal strip across them in a wooden holder. Slanted, so that you can see the nib, but also grab the heel of the nib rather than touch the body of it. Hmmmm.
Anyway, back to the original question, I do switch out nibs often, but keep my prepped nibs separate from my unused ones.