  I propose a variant invisible axion model of spontaneous CP violation at the
electroweak scale without CP domain wall and `strong CP' problems. Both large
size QCD and small size non-QCD instantons break CP and Peccei-Quinn
symmetries, and render cosmologically harmful CP domain walls unstable. The
decaying epoch depends on size of small instanton effects, and is around 100 eV
if the current neutron electric dipole moment bound is maximally saturated. The
model satisfies constraints from primordial D and He photo-dissociation and
black hole formation, while producing cosmologically interesting size of
gravitational waves and galaxy-scale density perturbations.
