This combo is a triumph of two otherwise mediocre cards. If you can collect four Stashes, then each time you play the Chancellor, trigger a reshuffle and place your Stashes on top of your deck for a guaranteed Province next turn. Repeat each time you draw your Chancellor.
One major advantage of this combo is that it doesn’t depend on trashing ability like most other combinations. True, it works better if you have no Estates and Coppers and can be assured of drawing your Chancellor quickly, but the Chancellor takes care of the usual issue of having to get through your deck. Similarly, it’s quite resistant to Curse-giving attacks, so long as you have enough Chancellors to draw one reasonably early in your deck.
However, the combo gets completely wrecked by handsize-reduction attacks (Militia, Goons, Torturer, Ghost Ship, Minion), as well as Masquerade, if played on your 4x Stash turn. Likewise, Possession can destroy this deck: either by Possessing your 4x Stash turn (by playing Possession on the turn after you play Chancellor), or by Possessing your Chancellor turn (and then sending your Stashes to the bottom of your deck). Note that everyone else can tell when you have your Stashes in hand! (In real life, the Stash cards have a different back; on the Isotropic server, the Stash cards are visible when you click Info.)
Moreover, the combo is incapable of buying Colonies. And the fact that both Chancellor and Stash are pretty terrible cards means that your engine will be quite weak until the combo is completed. (Compare to an engine built on Festival/Library: tricky to consummate, but still pays off handsomely even when incomplete.)
A Golem can be substituted for the Chancellor, but it’s more difficult to purchase. In addition, it’s more inflexible, since it requires that you have no other Actions in your deck.
Demonstrates a “Province rush” strategy on a Colony board. The Peddler is a decent option for a non-terminal that doesn’t stop you from drawing to your Chancellor, which is by far the most important card in your deck.