Perhaps If you stuff both of them into a sack and beat on it, you'll always hit the right one! is a bit like our If you throw enough mud at the wall, some of it will stick. If you attack something enough, then something is bound to take effect (although the mud and the wall one is generally about a person's reputation).
There used to be a saying that if you throw enough mud at the wall some of it will stick. Be enthusiastic and you will always sell.