This would, of course, lead to any individual, or entity, simply keeping 2 sets of keys. One legit, taxed, & one gray/untracked. That way, they could play either the clean or dirty markets.
But, they still couldn't launder, or cross between dirty & clean easily. They'd still need a collaborative cleaner in between... Such cleaners are easily built in the model you mention. (Out of country, with hands in both clean/dirty channels.)