The tricky part isn't money on a digital ledger. That's easy enough to handle with e.g. a one-off deposit tax (IIRC used as recently as the Euro crisis). There's no operational problem here, it just needs to be legislated to happen. Executing the operation properly might take a while (it's not something they'd have a process for), but banks must already have in place systems for e.g. freezing assets which could be used to buy time.
Bonds can just have a haircut on their nominal value, which is pretty much standard operation procedure during a financial bailout.
The real problem is deposits in foreign banks in foreign currencies. In the modern world by the time a country would be looking into this kind of a measure, a lot of the capital will have already fled. In this case the blocker is jurisdiction / sovereignty, not any kind of technical limitation.
> The real problem is deposits in foreign banks in foreign currencies.
Well, money abroad doesn't contribute to local inflation, does it?
I took the question to be on the logistics of executing this kind of operation with digital ledgers, not on when/whether those operations make sense.
Confiscating foreign assets would do little[0] to reduce inflation. But it's the same for local assets. Obviously just chopping off a zero from every note and bank balance doesn't actually reduce inflation, unless accompanied by some other structural changes.
[0] I say "little" rather than nothing, since it could have the effect of repatriating the money -> increasing the exchange rate -> making imports cheaper. But I can't imagine the effect being strong.
It can do; everyone you export to and import from still has the same money with which to buy and sell, and the same goods have different prices than you'd expect from just exchange rates in different markets.