For people like myself who need proof of onward ticket, I wondered if anyone used onward.flights and it actually worked.
Since these tickets are not actually issued (they are as fake as if you had photoshopped a ticket yourself), they would only work as long as the airline staff or immigration officials don’t care that there’s no valid confirmation number on them.
Probably you’ll be OK most of the time, but do you really want to get caught red-handed with a fake ticket (it’s forgery after all) or potentially be denied boarding and having to rebook your flight?
I would personally use either one of the services that actually issue a ticket on your behalf and then cancel it after 48 hours (worth the $10-12 if you ask me), or just buy a cheap onwards ticket if that’s available from the country in question.