How much epsom salt to combat dropsy?

Hi:
About 2 weeks ago I wrote a post about one of my favorite
goldfish, who had lots of problems, including an eye that was
completely clouded over.
Doing daily water changes and adding aquariium salt and melafix
seemed to help a lot, and up till today she seemed to be doing very
well. Good apetite, not hiding, red spots cleared up, and eye back to
normal.
This morning she has blown up like a balloon, and her scales are
pineconing.
This all has happened since yesterday.

I've done some reading, and it appears to be dropsy in its
full-blown final stages. Most of what I read offers little hope that
she will survive, but I'm going to try.

All the water parameters are good: ammonia and nitrite are zero
and nitrate is 10-20. PH is about 7.4 to 7.6. Water temp is 72-74 F.

I'm going out to get some rommet B food as soon as I post this.

Here's my question (finally). I've read that epson salt should be
used to try to help reduce the internal fluid buildup.

What ratio should I use?

"Goldie" still seems perky and swims OK, and she ate ok this
morning, but she looks like a blimp. This happened _fast_!

Any other suggestions?

PS: years ago I worked in a group home, which had a communal fish
tank. One day the fish died, and I was assigned the job of cleaning
everything up and putting the tank away. A week or so later I got a
terrible infection in one of my fingers. Over the next 2 months it
spred up my hand and arm. Several doctors could not diagnose it, and
numerous antibiotics were tried. Nothing worked. Finallly I was sent
to a specialist who diagnosed it as some type of mycobacterium. (sp?)
I don't remember the name of the med he gave me, but it cleared
everything up in about 2-3 weeks. I do remember that it was TERRIBLY
expensive. The specialist said that this bug was quite rare in
humans. I think I must have gotten it from cleaning the tank, but
I'll never know for sure.
However, ever since then I have tested positive for TB. I'm told
that this bacteria is some form of TB, although I have no symptoms of
TB.
Could this bacteria still be in my system, and could it have
somehow got passed into my fish tank? (I never wear gloves but maybe
I'lll have too from now on.)

Dave123