I am trying to anchor a 2 X 4 to hollow plaster walls. Well, I'm not sure it is plaster but it is definitely not sheetrock. I've tried hollow plastic anchors and Walldogs, but the anchors just grind through the wall material and break off. The wall has this sandy brittle composition that breaks apart when stressed. Is there something that might do the trick??
If you can't hit studs for some reason then I'd go with toggle bolts. You can't hang a lot of weight from plaster...If you plan to hang a TV or a bookshelf or something like that then you definitely need to hit studs.