Not true at all. Rockstar can see all the money you have. Whether its deposited in your bank account or its still on your hand. If they wanted to ban you they would ban you regardless of whether you deposited the money or kept it on hand. You can't hide the money you have.
Best bet would be to purchase legit Adders and upgraded them fully and fill up three garages on each character. Use them as a cash bonds in case you get banned and your money get reset.