I think with a glass tank all you have to do is rinse it REALLY well. I have two acrylic tanks (which absorbs bleach) and I always rinsed it really well, filled it with water loaded with aquarium salt (it's supposed to draw the bleach back out), and then rinse it really well again. Sunlight is also supposed to get rid of any bleach left over.
For gravel... I think some gravel absorbs bleach... so I don't know about that. Next time I would use the oven instead of bleach...
But in a large dose of a water conditioner that treats chlorine. Bleach is HClO, and the water conditioner removes chlorine, so it will remove the bleach. Use a lot, though, the concentration of bleach is a heck of a lot larger than the concentration of chlorine the water company puts in.
i have never used bleach for gravel, always have boiled them on the stove. Just rinse and rinse and rinse and soak them. You will probably have to do this over and over to make sure that the bleach is gone. I don't recommend you do this again.
The tank should be no problem if you rinse it well and let it sit for a little while with a good squirt of dechlorinator in the final rinse water. Then let it air dry completely.
Do the same with the gravel, but it's a lot of work to get bleach out of that. I tried bleaching some once and would never do it again. Unless you have expensive gravel, it's a lot easier to just replace it.
sounds risky, i'd never use bleach on anything that goes into a fish tank, just make sure 100% that there is no bleach still in it when you put it back in a fish tank, and just to make sure i would run a carbon filter in it for a while, that should get anything very small amounts that might remain?