All of them are speculative plays, no different from investing in the stock markets only with less potential upside.
What is actually happening with these huge deficits is central banks are loaning to governments at artificially low interest rates. In other words, printing money.
I'm still waiting to hear if that expert is putting his own money into 10 year government bonds.
Don't worry we can print money because we can create money on a computer with just a keystroke. Money grows on trees now and we all ride magical unicorns over candy rainbows. Cue John Lennon's "Imagine".