There are plenty of us that have "popped the grain" on a veneer. So there is plenty of info available. Remember to always use a test piece of wood first to get your technique and colour level right. Tru Oil will yellow over time so don't use a blue stain for anything as it will eventually turn green.

I use a very diluted black ink to pop the grain and then add more if required. Apply lightly with a clean, lint free rag, a very light sand afterwards to smooth the grain, then it's ready for a stain or finish. Be careful not to get the veneer too wet as it can loosen the glue and bubble the veneer. It's better to add a little at a time, cause you can't take it back out!