So you do ask questions which should cancel each other out?
In the context of the riddle, you could only ask one question of one of them, knowing that one lies and one tells the truth.
To format the question in a way that would reveal where to seek you would ask "What location would the other guy say IS NOT the location that reveals your secret information"
The question needed creative wording so that it works in reference to a binary choice in the original puzzle. The question phrasing is intended to represent the choice in a binary choice:
The location you want | everywhere else.
In this case, If you ask the Truth-teller what the other (the liar) would say. He will give you the sought location. He will know that the Liar HAS to say the location that DOES reveal the secret information in order to lie. Since the truth teller knows exactly what the Liar will have to say, he has to relay the information on to you truthfully.
If you ask the Liar, however, depending on how he processes his counterpart's logic, you might not get the right information, or any information at all. The Liar will know that the truth teller will not say the location, since you ask for not-the-location. He's required to lie about what the truth teller will say, but he only has nebulous information regarding what he would actually say (unless he has insight into truth teller's exact response. If the requirement to lie to the best of his ability is maintained, and he doesn't know exactly what the truth teller will say, he will only know that the truth teller will not say the appropriate location. In order to uphold his requirement to lie, the only safe way to do it is by saying the truth teller would give you the location that DOES reveal the sought information. We can't count on it, though, if the Liar knows any other place that the truth teller would definitely not mention, he's only required to tell you a lie regarding what the truth teller would say, not regarding the answer to the question you would be hypothetically asking the truth teller.
Really, though, this does boil down to the nebulous nature of a lie when multiple choices exist- that's why in some versions even with a binary choice for the seeker, the tellers will only answer yes or no, and you must gain the information via a yes or no question : would the other door say that he is the path that leads me safely out.
Edit: I'll also leave this here
https://en.wikipedia.org/wiki/The_Hardest_Logic_Puzzle_Ever