Note, if you looked up a domain and it had no results, you should check back again after some minutes. I looked my domain up and had zero results, which was weird as it should at least find some in the ct logs, but a few minutes later it showed some subdomains.
It took about 5 minutes for me. It found my apex domain and a sub-domain that must have belonged to the previous renter of my domain name. [1] So I was curious and it turns out the previous renters pages were in Wayback. [2] That page renders as mostly little boxes for me. Funny, I had never bothered to check that. I should check if any of my other domains have snapshots from before I rented them.
Web archive can also somewhat act as a subdomain finder (not really in this case, only the www subdomain, but still interesting):
https://web.archive.org/web/*/ohblog.net*
