I have done it. It can take several months to cure. Dissolving the salt should be the least of your worries.
I actually ditched mine after about 2 months of curing. You can make it cheap but you can also find great deals on craigslist and not have to worry about changing water for 2+ months and waiting all that time before you get rock in your tank. I found 75lbs of live rock on cl
It just didnt make sense and I will never do it again. A guy on here greenmaster I believe actually put some he made in the ocean for like a month or so and still had problems for a long time with it when he put it in his tank.