I don't know your group, but you can remind them that they mark experience when they roll a 6-.
This is something that few games do this well: *World games 'encourage''encourages' (some might say 'bribe', but not me!) players to take certain actions by rewarding with XP like nobody else! And they do it without remorse. It might be considered metagaming in some systems, but *World games have redrawn those lines.
I just mean, that they might be more likely to spout lore if they know they will be marking experience when they fail.