Maybe they can take an approach like Cambodia, where USD is the unofficial second currency. Given bank ATMs dispense USD, I have to wonder if it was the main currency in circulation.
Have the Drachma return, but have the option to use the Euro where appropriate. I have no idea if this would help anything, just noted that it's possible. It shouldn't matter which is used at the end of the day, I guess with the Drachma it's just easier for the government to tax it indiscriminately (indirectly) through the printing of money, without making it so obvious.
