Who's going to escrow 20 million euro in cash? This could mean jail time for money laundering!
There's also no point: I've seen so many "offers" here, ranging from millions to billions of dollars, and all of them have in common that they can barely write a full sentence. If I have to guess, they'll either ask for a small "test amount", or just rob you when you really meet up.
A 2/3 escrow I was thinking.
1. Three cosigner create the wallet.
2. Both buyer and seller meet at the spot
3. Buyer give the cash to the seller
4. Seller confirms and escrow release the BTC.
Or make it like this. Since this is a lot of money, the escrow will have a condition like one of them will travel to the spot. Be invisible to buyer and seller but he will watch everything from distance.
2. Both buyer and seller meet at the spot, one of the escrow watch it from distance.
3. Buyer give the cash to the seller. Escrow tries his best to judge the situation.
4. Seller confirms and with that the one in the spot watching from distance confirms as well
5. The two cosigner release the BTC.
It sounds thrilling but possible, isn't it?
How much money you consider is enough for money laundering?