Is there some way to make Anti-Freeze Bottles (or Berry Mentats) spawn more often?

[TropBlueMR2GT-S]

I might be on a cold streak of luck, I keep hitting up my usual rapid respawning spot in the game but so far have only found ONE Anti-Freeze Bottle. Last playthrough I would have had at least 4 or 5 by now. Perhaps I'm being impatient. Does anyone know if there's anyway to make items like Berry Mentats and Anti-Freeze bottles spawn more often? Like for example maybe put a few more points in the luck tree? Or am I pretty much doomed to them being a constantly very scarce source?

Going for a Max Intelligence build here and I need tons of Berry Mentats to make it work for speech checks and turning in quests and what not.

[Tavman (4)]

Try this:

http://fallout.wikia.com/wiki/Anti_freeze_bottle