It has been some time since I have destroyed a few piccolo's. It has also been some time since I touched any

. Ok that happened in one accordion and I was learning.
The two keys to scratching or filing any reed is proper reed support, AND, the right angle on the implement of choice.
For proper support I have used strips of metal banding shaped to fit the reed hole (in the reedplate) and support the reed. For outer reed support this is a little more tricky but the alternative is potentially bending the reed because the support you are using is too thick and voila (via feeler method), goodbye voicing. Initially this takes quite a bit of time to shape (file) and bend the piece as needed, but the lack of stress during tuning is totally worth it. I would rather have something out of tune than messed up voicing, so I don't use feelers for these anymore.
For filing (inside reeds), I use a stick with some fine grit sandpaper glued onto it, fit it into the soundhole of the reed block and sand towards the tip, never the other way (or you will fold the tinfoil). Outside reeds I will also use sandpaper when they are that small.
Mostly it is all in the preparation of the reed support, everything else is easy.
Two other things that aid greatly are a) 6.0x reading glasses (so you can properly see that your sanding or filing angle matches the reed angle - thereby not folding the reed) and b) light. I have several lights from different angles, but am really liking my headband LED light, that is in itself a band of light. This kind of thing >
https://www.amazon.ca/Rechargeable-Flashlight-Headlight-Adjustable-Waterproof/dp/B09KCB8Q4R/ref=sr_1_2?crid=CI8FH7A7V7TB&keywords=headband+led&qid=1696290805&sprefix=heaband+led,aps,171&sr=8-2&th=1
Even just posting this stresses me out thinking about it
