Absolutely terrible advice. Successful or not, once a TM owner finds the domain (plenty of ways to do that without it being popular), they will request it. It would suck to invest a lot of money and time only to lose everything and have to start over again.
I think you should think about a Brand name. Maybe in the future it is going to be your Brand. Who knows.....
As I said is for fast money, I also said will have a lot of troubles due to TM. Is not a terrible advice, is the truth pal.