As so many things in the Army, it depends on your company and DS.
During BCT three years ago at Ft. Leonard Wood, my DS would encourage us to exercise if the address was screwed up in ANY way. You have to love friends who send stuff with hearts and 'stuff' drawn on the package.
As for goodies, our DS would allow us to share baked goods toward the end of the cycle - as long as there was enough for everyone and it was all eaten during the mail call. Some people opted for the DS to hold the package with the contraband until the end of cycle.
So the moral is ask your son in a letter what actually happens to goodies, then send them if you like the response. Remember, you don't really want to surprise him with anything during BCT - surprises usually equate to attention which is something most Joe's don't want.
Jamie P. Rigoni
STB, 86th IBCT, VTARNG
Vermont AMEDD Recruiter