T for a virtual particle is no time at all.
If the annihilation of virtual particle happened in a heavy medium it might take more time than zero. at any rate Dave a black hole does not power virtual particle. A black is a neutrino factory compared to the negligible loss of mass by half of a virtual particle now and then.

Hawking was still trying to defend his loss of information via a black hole theory when he came up with his 'virtual mass loss' idea.

When black holes over eat, the amount of energy from the reaction of matter is annihilated into energy we see as gamma ray energy blasting out the poles of black hole. Why the poles? Because of the convection currents of energy reduced to energy and neutrinos unable to compress beyond neutrino size.
Neutrinos at a near massless particle are able to escape an event horizon well enough to be concentrated around the entire black hole.

There will always be more :neutrino radiation" than theoretical "Hawking radiation".

What to carry away is the fact black holes will be around a long time in increasing numbers to reshape the sponge like foam of all the mass in the universe. Today the universe is like a sponge with small holes but in another 15 billion years the universe will look like a sponge with LARGE holes all due to black holes and space expansion.