the danger with asbestos is when you inhale asbestos dust.

Having set out side for many years and hose it off, if in doubt, paint it with lead based paint

(j/k about the lead based paint, using a good coat of paint will seal it for any stray particles that may have survived the years of exposure and the hosing off)

Personally I would just look for any dust residue and call it good if there isn't any, FWIW I did Asbestos tear out in another life.....