I go to each character, convert that dil to zen. Then I go back to my main, and convert that zen to refined dil. And viola, I have subverted the 8K dil rule on that character by a very much intended mechanic.
Erm, there's already simpler method that's been advised on this topic. With every alt, you make offer to buy zen that no one will accept (like 25 dil for 1 zen). The way Exchange works, it will take your dil and wait for someone to purchase it. Then you switch to your main and cancel all those offers - dil ends in account pool, and then you simply retrieve it.
I tried to explain this once to someone in tells, but before I got to do that I was called a cheater and put on ignore. Just can't help some folks.