Curing dry rock

[zhasan]

Reading the posts above and watching some videos on youtube, I've decided to go with Muriatic Acid bath.

Its -20 outside so I'm thinking I can't perform this task outside.

I would do it in the garage, but would the cold affect effectiveness of the acid reaction process? Also, If I have to let it sit for about 1/2 hr or so, it might start to freeze up but maybe not if there is heat generating due to the chemical reaction.

I'm wondering if muriatic acid rec a fiberglass bathtub?

As far as the process is concerned, here is what I've learned so far.

Fill up the container with rock and submerge it with normal tap water.
Slowly start pouring acid in the container up to 10% of the water volume.
Let sit and watch the magic happen.
Add baking soda to neutralize the process.
Dump out all the water
Thoroughly wash the rock and let dry for couple of days.

Would those who've successfully completed the process, please confirm if I have it down right?

thanks!