> I better take the glass off and clean it.
Use fine Brillo on a toothpick, then flush with boiling nitric acid.
> Just kidding... I put the tube in the trash.
That's like the Three Stooges, throwing away half the nails because the heads are on the wrong end. Dummy, those go on the other side of the house!
Seriously: tubes with a mild hiss are fine in higher level stages, preamp outputs or power-amp driver stages. Hiss is mostly an issue right AT a passive pickup (mike, gitar, phono) or volume control wiper. That stage has gain of 10-50, so the next stage can often have huge excess noise and it won't be noticed.