Best way to do this is farming MINAC. There's a hiding place on the map where you won't take any damage and you do not have to destroy any turrets and/or spawning claptraps:
When you enter the combat area go to the small alcove on the far right corner of the map and hide behind the dumpster on the right side. Once hidden, you can go to sleep or do whatever you want. MINAC will kill all spawning claptraps or they will kill themselves by exploding.
Next step: kill MINAC and INAC, then collect the stuff you need.
I farmed for about 9 hours and there were enough panties, Pizzas, bobble heads, clap fishes, oil cans and 3D glasses for all the collecting achievements.
Hiding place on the map:
http://steamcommunity.com/sharedfiles/filedetails/?id=538377...