Cleaning baby’s belly button

[StiffUpperNip]

My baby is 16 weeks and there looks like there’s quite a lot of gunk in her belly button. I did a quick surface swirl with a cotton bud and some coconut oil, but was scared to go too deep and clean it thoroughly.

I’d quite like to give it a thorough clean and she was completely unbothered, but thought I’d check first. Is this fine to do? I’m not going to disturb anything at this stage? I can wash while giving her a bath/clean with a cotton bud? It’s fine to use coconut oil?

It’s surprisingly hard to find info online. It’s all about newborns’ belly buttons.

I had similar with my eldest. Washed it regularly with a baby sponge twisted into a point and lots of baby soap, wasn't brave enough to do more than that. But there was one black patch that I just couldn't get out and it didn't disappear until well over a year old.
My youngest had an umbilical hernia so much easier to clean but he still had what looked like dirt on it for almost a year, despite the easy cleaning access.

So I wouldn't be too vigorous since in my experience it's fairly normal. Just clean gently as best you can.

Thank you so much!