Search:

Another thing one needs to assess is how acidic one's skin /sweat is to carbon steel. I don't think that is the case with the OP as it more likely would manifest as rusty fingerprints.

It is possible but of course water played a big part in creating the rust.

Good job !

On a previous point, I always use toilet paper to remove lather but a dry towel is popular & fairly traditional too.

If you support the edge & body well you can rub it in gently with one of those disposable chopsticks that look like balsa.
See how you fare but I doubt you'll get rid of the pitting.

Katana have the added advantage that they are stored in a scabbard but yes Camelia is fine for razors . Just not long term storage without refreshing it.

If anyone knows their chemistry they might chime in with just how acidic some fatty acids (oils) are or can get when oxidised.

Congrats on a good start, however, do you know the ingredients in the pre-shave oil to entrust anti-rust qualities to it. ?

Looks like you also have rust in the middle of the edge. It will eventually chip. I guess you can wait for it's first honing but it may be soon.
Metal polish may help with the stains but may also...