To clean some cash, start small and start now.
The idea that one can 'wash' a six figure roll quickly is a pitfall to avoid. No matter how well you cover it, people get suspicous and jealous when a young guy has more money banked than they do. That goes especially for bankers. If you go to get a loan and you have more banked than the loan officer, they get suspicous and they start to ask questions and they dig, then your screwed. No matter how well you think you cover your tracks, if you do too much too fast you will leave a tell or two that someone more financially experienced will see. Then they tell the cops, and that makes you a sad panda. On the other hand, if they dig and find you've fixed up and flipped a half a dozen houses over the last five years, or built up then sold a cab company over a decade, well then, you are just the guy who's ass they want to kiss.
I agree 100% with the posts that say do a little at a time. Do a little, and do it right away. Then...do some more.
Work toward banking a realistic amount on a regular basis. Read all the money management books you can. They are full of 'bright ideas' that seem like they'd all work a lot better if you had a roll of cash under your mattress. Wait a minute......you do. Good. Read up and figure out how to apply the knowledge to building your business.
Get a retail sales permit and a tax number. Start a business. Even if that's just weekend flea marketing. I'm not saying that you can declare it all as sales that didn't happen (that would be illegal and obvious. don't do that) Running a little business will show you how it works, and lay the foundation for running something more.
Start small, start now.