Well, DR might not necessarily stop you. Special materials and all that, and since they aren't ammo it isn't too hard to just find your thrown items after a fight. Alignment might end up being a pain though.
But it does make another situation where sohei has a technical advantage over the archetypes specifically designed for ranged combat- sohei apply their ki strike to all weapons in their weapon training group (which includes thrown weapons). So a sohei could have daggers treated as cold iron, silver, or lawful (which can be switched to good/evil with a magic item, actually).
The far strike monk's ki missile ....might...do something similar, but it costs 1 ki point, while sohei gets ki strike on their stuff for free.
The prayer wheel of ethical strength, which is a 10k item from ultimate equipment that lets you turn your monk's ability to hit as lawful with ki strikes into good or evil instead.
You just use it when you rest or meditate to regain ki, and boom- you hit as a new alignment until the next time your rest/meditate. So fairly much constantly, unless you lose it somehow. And I suppose you could share it among the party if you somehow have multiple monks.
just a note: this item is technically two different, seperate items (each costing their own individual 10k)- one covered in sacred mantras for good, one covered in...I don't know...heavy metal lyrics? for evil- obviously the good one is far, far more useful most of the time.
