Will I be able to remove this watermark?

[waltzingparrot]

This is an interior wooden step that had a houseplant sat on it. I presume water got splashed over the side and on lifting the plant up, I found this. It's oak, that has been regularly recoated with recommended linseed oil.

I've tried three suggestions from the internet, vinegar/olive oil, toothpaste (both unchanged) and mayonnaise (minimal lightening).

Any commercial products that might work please?

When this happens in our house I just put another plant on it

You could try ironing over it with a towel underneath.

Oxalic acid on the dark edges only of the splodge. Barkeeper's Friend contains it.

@NigelHarmansNewWife Thank you for the tip. I'll give Barkeeper's Friend a go.