:Draco18s, I don't really follow your method; this is for 500 blocks in a single chain, but your method sounds like it's going for as many blocks as possible in a single combo, which doesn't require trickery (though it definitely benefits from it). When your large chain finishes and the blocks on top drop and fire streams upon landing (thus continuing the combo), you're back to square 1 in terms of large chains. Unless I'm missing something, you won't get a chain of more than 144 blocks.
My best method for doing this uses zen trampoline with 400 frequency red, 200 frequency eater, and a flood item. You can clear the starting set of blocks or just put some eaters at the top of the screen to get everything started. Then you just use the flood item and watch the magic. Before this, I was doing zen trampoline with 400 red, 200 eater, 200 quad repeater and making new blocks that fell point to the opposite side of the screen so they'd cover the maximum area and thus would be more likely to hit a block or quad repeater. The new one is better because it just requires one click and then it should do its thing indefinitely.: