Any way to "line" a kitchen cupboard?

[candycane222]

We had our kitchen cupboards made bespoke 25 yrs ago, for the wonky -shaped space in our old house , with very nice hardwood worktops that have aged really well and still look lovely. BUT there are numerous crevices in the construction eg behind the battens that support the worktop that obviously have something living in them , as a light dusting of -um- frass ( 🤮) appears in little piles in a few places.

Although presumably one solution would be to rip the whole thing out and start again , we can't possibly afford to! But we are probably not the only people to have had this problem.

I am wondering if there is some kind of product (I am imagining a kind of gloopy paint) that could be used to seal the inside of the cupboards, including the minuscule gaps where the battens sit against the plasterboard etc, so the creatures that we can't necessarily eliminate, are fully separated from my baking tins, measuring jugs, etc.

Just use some caulk or clear silicon maybe?

Seal gaps with silicone/ caulk and put flooring vinyl over the top.

Could it be woodworm? You'd want to check for sure.

Is it worth using insecticide or something first?

Caulk is a good shout, don't know why I didn't think of it - I guess I was hoping to avoid the extreme contortions involved to get to some bits ( and the caulk would be put in upwards too iyswim)

And yes, wondering how to kill the beasties. Don't want to use anything too toxic - or that would stop the caulk/paint/whatever from sticking 🤔

I guess itll be hot soapy water and a scrubbing brush, then a fan heater afterwards to get it properly dry?