Kat;As noted, if you didn't declare for one of the three 'major' religions they offered, you were left behind in the barracks.
During the 3-4 hours that you spent there, you could count on the up close and personal attention of your Company Commander, who as noted was NOT usually happy at being made to sit around and babysit you. 4 hours of intensive cleaning and "punitive" exercise sessions without break will make just about ANYONE reconsider agnosticism.
M