For many PA programs shadowing doesn't count as clinical experience, what they mean is hands on clinical experience usually in some profession capacity that requires a certification such as RN, Respiratory therapist, EMT, Paramedic, LVN, Radiologists, surgical tech, CNA, and sometimes phlembotomist, etc... 3,000 Hours is about 1.5 years @ 40hrs/week. Do you want to shadow a doctor for that long, lol?
Best bet is to find a program, do it for 1-2 years or less if accelerated (EMT, Phlembotomist, BSN) , get a job in the field and do it for 3,000 hours. Also, you should broaden your scope to other schools because 3,000 seems on the high range for clinical experience, most require 2,000 hours.
I'm am in the same boat, but have a Science Degree and most of the pre-reqs with little clinical experience looking for an accelerated program of sorts and if not a 2 year certificate program.