How do we repair a solid wood worktop taken down to the bare wood?!?

An oil air freshener spilt on our solid beech worktop and someone who shall remain nameless then went on to soak the area in Cillit Bang and scrubbed through the film right down to the wood- it's now a complete mess with a stain & marks about the size of a dinner plate. Can we sand it down and re-varnish or what have you?! Desperately in need of some help on this one!! No idea of make & model as was in here already- solid beech like a butcher's block.