Welcome to the Forum...was it extra hot when you were camping? Was it windy? Hot weather can cause the tanks to smell even more. Possibly you were actually getting some odor from the vent pipe and not from underneath.
Anyway, after all that filling and emptying, you now have a couple of clean tanks...:)
"If we couldn't laugh we would all go insane."
Arctic Fox 25Y
GMC Duramax
Blue Ox SwayPro