Allot of people asking this question many times that do dummy tickets really works or we should stay away from it. There are lots of forums on which people say stay away from it and buy a refundable ticket but you know refundable or other tickets cost very much and people don't want to waist their money on such tickets for only showing proof because there are more than 90% chances that this onward ticket they might not use it. They might stay more or plan something else.
Where dummy tickets work actually?
Dummy ticket works and as a digital nomad I myself have used dummy ticket most of the time and it got accepted. One of the officer itself tell me to use dummy ticket generators for your proof of onward ticket.
There are certain things which you need to keep in mind, one is you have to follow the rules of the exactly country where you want to fly. if in your case there is written that onward flight reservation accepted then it clearly means you can show them dummy ticket. If it says booking only accepted then you will need a full ticket and dummy ticket will not be accepted here. most of the countries accept dummy ticket and reservations, only few countries have strict rules regarding it.
What if my dummy ticket got rejected?
First of all if a country rules says we don't accept reservation, only booking is accepted then in this case you don't need to present a dummy ticket otherwise they will not accept it. secondly if they accept reservations then there might be some problem with your reservation that they will put in your rejection reason.Some time reservations also got cancelled that might be the reason but Its not a big deal, just make a new reservation and give them back.
My own experience using dummy flight tickets
I have traveled over 35 countries and mostly I used dummy tickets where acceptable but till now non of my dummyticket got rejected. I use this site Dummy Flight Ticket for all my dummy tickets generation. Most of the countries don't have such strict rules. you only have to dress well and present your onward ticket it actually works. I am telling you by my own experience. not any single ticket of mine got rejected.
Why People say stay away from dummy tickets?
Most of the people don't know about a dummy ticket and they consider dummy ticket as a fake ticket which is actually not true, a fake ticket is having no reservation record online and you cannot verify it online while a dummy ticket is associated with a reservation which you can verify online and its actually a seat which is reserved for you for a specific time period after which you have to pay full amount otherwise your reservation got cancelled. A fake flight ticket and a dummy ticket looks the same but only difference is online verification which I have explained above.