I think the skill has to get involved somehow. The system generally using those to modell the world, the same way as attack rolls represent martial skills of the character, which can be very high even when the player can't even hold a sword straight IRL. Social skills (Bluff, Intimidate, Perform, etc.) are not exceptions from this. If I want to play a bard, but I am a lousy performer as player, I use the skill (of course adding some RP is neccessary). Because if it is not allowed, it would be the same thing as saying I can only play a monk if I (as player) have black belt in a martial art.
If the character thinks the other lies to him, he should notify the lier character's player OOCly, and they have to OOCly agree on the spot how to resolve this with rolls. Please notice the words 'character thinks'. Some idea to this:
It can even be agreed, that he character has no reason to suspect the lie, it is just a player's knowledge which makes it obvious, in this case a bluff roll vs. the character wisdom score as DC could be enough, really just checking that the liar makes a mistake, which the other part could notice (sweating palms, twitching eyes, etc). "Honest" liar players can volunterily making this roll in cases the player doesn't know about the possible lie, but his character should. (Example: newbie player plays a native Sanctuarian, lieing to his character about the city is hard, even if the player has no info on this.)
If the lie is about something specific, a roll vs roll solution could work. Like lieing about some geographical or historical info is bluff vs lore (lore is highly abusable in this term, so try to find an other skill if possible first). Lieing about a magical topic is bluff vs spellcraft. Lieing about a trap is bluff vs. disarm trap. If nothing else could be find a bluff roll against DC the character's INT score can be the solution. If only the lier could blow the thing, as the character has no info on te topic, a bluff vs bluff roll can do the trick. Whatever way it can be decided, that the lie went through, or not.
If it does, than time to go back in IC, and playing out the results accordingly. If not than the cheated party can decide to react on the lie, and confronts the liar on the spot, in this case again back to IC mode and play it out. However the cheated person can decide, that he hides the fact he discovered the lie. In this case a bluff vs. bluff check could be the solution, and the winner of it gets the good assess of the another. If the cheated person wins, he hid the fact that he is aware fo the lie. If the liar wins he knows that the other person saw through him, but tried to keep it hidden. No further rolls are neccessary. Time to go back in IC mode, and play it out accordingly.
I know it involves a lot of IC-OOC knowledge separation, as well mature players. But maybe this could simulate the whole situ acceptably and quickly with one or two rolls. It is easier done than described.
It is my 0.2 cent only, I hope at least some can use it and play great scheming liars. :)