How to delete unwanted thumbs?

hi all.

I’m running out of space on my iPad (who isn’t?! :-p)

And found Kodi has 1.2GB of thumb cache.

I had this problem before on my pc and decided to delete the lot, but this also deleted tonnes of over useful thumbs like icon graphics and the like.

Is there any way to delete ONLY the cached video/music/pictures ‘artwork’ (if I can use the term loosely) without binning tonnes of important stuff?

Ps- I’ve tried ‘cleaning library’ in the settings, but no significant change.
Cheers