wp menu list --format=ids | xargs wp menu delete
wp post list --post_type='post-type-here' --format=ids | xargs wp post delete --force
wp eval "\$posts = get_posts( ['post_type' => 'post-type-here', 'numberposts' => -1 ] ); foreach ( \$posts as \$post ) { update_post_meta( \$post->ID, 'field-name-here', 'test' . \$post->ID . '@example.com' ); } echo 'Done!';"
for i in {1..150}; do wp site create --slug="test$i"; done;
(If using fish, try switching shell first with sh
.)