Only thing that has mehelped so far..
I believe I had a decent infestation (5-8 beetles a day) that emerged out of nowhere. I used diamatrecous earth and it sorta helped, however, I think I needed to add something else to take care of the issue and I seen this in another forum. This spray seems to kill them on the spot and when they walk in it. The smell isn't too bad either. I got it off Amazon, it was around 20ish dollars.
I sprayed the entire perimeter of my apartment and sprayed where I believe they like to hang out. The directions on the back for carpet beetles specfically states "apply a sweeping motion as a surface spray to carpet, rugs, closets, baseboards, upholstered furniture, and around edges of carpet" and that is what I did and so far I haven't really seen any. Hopefully this helps someone else, I cannot live like that lol.