I'm somewhat amused by this investment vehicle you've proposed. Hire a sketchy-looking dude in a van missing a taillight to courier your cash. He gets popped, but isn't doing anything illegal, maybe has a pre-rolled joint in the glove box, so they seize your cash. Every day it's tied up, you're getting serious returns. Eventually, submit the courier contract to prove that the cash wasn't being used for crimes, and reap that interest.

I see this cop-baiting practice getting criminalized long before civil forfeiture.