StillSmart

Unless its paint I probably wouldn't bother.

Use coarse paper - across the grain - in a belt sander. Orbital will struggle.

Getting there now. Keep going back to it as I'm currently on a job.
I've sawn off the grotty ends and sanded a fair bit and the change in smell is incredible.
Started off not really smelling and now it smells bloody lovely!
I've left a bit of the inside char on and am planning on putting it in the oven in the next couple of days. Although at this rate I'm not sure it needs it.
Can these blocks be reused or should I treat them like the chips?

Re usable - store them bone dry or freeze.

For what it is worth, I have been making my own Oak Match sticks for aging for a while now from retired distillery barrels.
I simply plane down the staves to clean wood,cut to length and chip/split to thin pieces.
The end result to me is worth the effort.

And IME they could be good to re-use a couple of times, with diminishing volumes. I keep my resting ones in a "plastic" bag in the 'Fridge.

Robert.

A belt sander or power planer helps tremendously with this.

Robert.