Here's the situation. There's a locked door that prevents any further progress into the dungeon. There's a keyhole in the door and a message basically saying that the key needs to be wished for.
In the room with the locked door is a wishing well. Each person is limited to one wish, and successive attempts just inflict damage to the wisher.
It's very straightforward: someone needs to wish for the key and it will appear, and they can unlock the door. The intent was not to present the players with a complex puzzle or anything time-consuming. The intended effect was that all but one player get a free wish, but one person has to sacrifice their wish to get past the door (and later be rewarded for their selflessness).
But, as always, things did not go according to plan. Without even discussing the key, each character went ahead and made their selfish wish. Okay, no big deal. You can brute force the door or just break it down with an axe. But my players are terrified that something awful will happen if they destroy the door, even though I have done nothing to indicate this.
They've tried wishing for the key, but since they all expended their wish, the well just damages them and doesn't work. So they've now set their mind to solving this puzzle that doesn't exist. They are trying to find deeper meaning in the words on the door, trying to word the wish more precisely, taking unnecessary damage all the while. The last 30 minutes of our session was spent on this.
Now I'm all for causing a little party frustration. But it's starting to drag on. I want to explain to them that they've simply exhausted their wishes and need to find an alternative way to get past the door. I want to smack the fighter over the head and tell him to just bash it down. But that's not the way I roll (heh, heh).
I would provide subtle clues - the magic aura of the wishing well fades, or something along those lines, but the damage has already been done. They've inspected the well and the door and I've already told them that there is nothing different about it.
How can I get my players to overcome this obstacle without just telling them outright?
Note: I appreciate all answers specific to this particular situation, but I would also like more generic tactics to deal with unintended obstacles for when this inevitably happens again.
Here's what ended up happening: I provided a few more subtle clues that additional wishes weren't going to do anything. They decided to give up and go explore the rest of the dungeon for missed secret doors. By that time, the enemies on the other side of the door had heard the PC's and had plenty of time to plan a surprise attack and coordinate a tactic to corral the adventurers into a sacrificial pit in the next room. So just as the players started to move away, the door exploded inward in and battle broke out.