I dont think you can only thing you can do is make sure you buy it from a shop and then least your not being tricked by there asdmins etc
Not sure how you're getting banned, I seem to trade bills over easily, but ye they can check drop logs, trade logs so only safe way would be dying to monster and then picking up, but in honesty you should just trade it over as it looks more legit than trading, but yes as stated above you could also gamble it, but you would probably need mm or dice bags, and obviously you can't use mm, so you'd just be trading it over anyway lol.
I traded over 50M + 150M and got banned lol. I've tried the trading post, got banned. hmmm I'll have to try the NPC method
They have so much of the staff dedicated to preventing RWT, at this point its not worth it. (i too get banned 9/10 times)
I suppose you could claim to be doing a hide and seek giveaway or something of the sort, and tell the person buying the gold to just meet you exactly where you are and then give them the items/gold.
They are trying hard to get the competition away, lots of owners have their admins rwt, I'm almost sure it's 100% of the big servers who do it Prolly those dudes who have like 10k vouches