Any tips on how best to clean the hook part of velcro?

Always have my overshoe velco almost completely clogged with organic matter and it’s a pain the get it all out!

Another strip of velcro?

Small wire brush from a DIY shop, (tooth brush size), they normally come in packs of three bristle types. workd very well and cheap!

Good tip Marcus7 will try the brushes. I usually use a cocktail stick to “pick” the bits out, works but fiddly and takes a while.

Many years ago I did a conference for southern water who had been bought by Scottish power iirc. The sewage workers were none too impressed with the lovely new boiler suits they had been issued with that had Velcro closures.