I would accumulate the cash on a few mules, but I would give the mules like 35 WC or something incase you go away for a period of time and Jagex does another account wipe (like they did before FT came out)...I'm pretty sure as long as you had 1 stat over 30 you were good.
When you feel you are done accumulating cash (unless you sell it for IRL $, IDK), transfer it all onto 1 noob account, go north of the Mind altar to the edge of wild on your noob and your main (separate IP's, for things like this I go to an internet cafe for 1 account and have my laptop with wireless internet for another account [protects my MAC address from showing up on both accounts]) then drop trade it in level 1 wild.
The reason I would drop trade in the wilderness is because other than nobody being around, the cash will show up for your other account instantly rather than waiting around.
That way there is no account interaction in any way
If you got a ban from ^, which I don't see how they can work up the balls, you could say you saw some suspicious level 3 sneaking around north of Fally so you followed him from afar to see what he was doing
EDIT: And yes, I love being a femme fatale secret agent type.