There are a ton of $2 cards in this game that throw a small amount of support toward Counting House, but few of them actually make it a competitive card. Candlestick Maker is an exception.
Candlestick Maker provides just about everything you could want for a Counting House deck: extra buys, non-terminal, and a way to hit important spending amounts later on. The ability to fill your deck with extra Copper and more CMs while saving up for multiple Counting Houses gives this slick little $2 card the power to make a fully functioning menace come later turns.
CM/CH is a numbers game. Your goal is to get a mixture of 8 - 12 Copper, 4 - 6 CMs, 4 - 6 CHs in your deck, and perhaps a Province or two by turn 11. Starting turn 12, you can spend 5 or 6 turns just buying points every turn.
You really want to delay your third shuffle with this deck. If you can buy 5 cards in the first 5 turns, that'll add another turn before that reshuffle, with the possibility of a good CH turn on the back-end. Early turns in the shuffle, you should spend your extra buys on Copper since they'll get caught-up with any late CHs you draw. The later in the reshuffle, the more willingly you can spend tokens on CHs and other CMs. You'd really like to have at least 5 CHs going down the stretch so that the possibility of having one every hand after the 4th reshuffle is more likely.
I'll try to get so games up here so there's a visual, but I've done well with this deck in both Province games and Colony games. Candlestick Maker really does everything you want for Counting House, save making it more reliable on the reshuffle. I haven't tried mixing in other cards as the kingdoms didn't seem good for it, but I imagine sifters like Warehouse would work well.