Yeah it might illegal, BUT it is how the system works in Indonesia.
I was in a taxi cab one day and as per usual was chatting to the driver, as always they are asking about you, I said I worked in law enforcement, the driver said his son wanted to be a Police Officer BUT there was no way that he could afford to pay for his son to be accepted in the Police Force.
So I asked the question - how much does it cost to get in.
The official entry is pass the entry requirements - same as any job anywhere in the world.
Unofficially the bribe to get a job was 5 x the taxi drivers annual income.
So what tends to happen is families will take a loan to get the money, most likely from a Islamic source (bank or private lenders) and then pay interest on it.
So once the young man gets in, and starts to work - he needs to pay back this loan. So the only way he can afford to do this is to find a way to make some extra income.
So where does this extra income come from - Bribes.
I would love to see a bribe free world, but its not likely to happen, when it is in the culture.
I am not saying it is the right way to live or to do business, I am saying this is how it is, and this is why it exists.
Up to you if you want to stand in a long line up at Imigrasi - maybe waste an hour or two of your holiday - or if you want to expedite your arrival processing and help a family pay off their loans.