I don't think it's a good idea to put your block in acid like you describe. I don't think it's safe either.

Just give it a good wash. Personally I'd use Diesel or Kerosene or Petrol and a tooth brush for the oily bits, for the coolant side of things just back flush with clean water till the water coming out is clean.

You can buy a honing tool for ~$30- to go in your drill if a hone is all that it needs. The members here can probably help a bit more if you put up some photos as you're stripping it down. The best way to tell if the block needs a hone or a re-bore is to measure it (the service manual should say how to do that). You'd be better off doing nothing than using emery paper by hand in the bore. That just won't work.

Good luck and happy learning.