Domestic remedies will not clear this up (voice of bitter, hard earned experience speaking, here), but ear drops in advance of your visit may serve to soften the wax (and ensure that it is easier for the medics to remove when they inevitably have to attend to it).
This would be ideal, yes, but as it's almost half past ten in the evening here, and the 24h pharmacy is a ways away I think I'm just going to wait until I get to the doc in about 9 hours. I have the whole coming week off, so luckily there's time to tend to it properly at least.