Ive been following this topic with much interest, so decided to have a go myself,
I got a bottle of clear malt vinegar and added some rusty nails, well over the past few weeks, i've tested it and its been getting stronger by the day.
Well I clean forgot all about it, then just now whilst me and my misses were watching a thriller on tv , we heard a the sound of a window breaking,, well we both jumped up right and searched the house for what we thought was someone trying to break in.. turns out my bottle of vinegar ,, exploded.. yep I forgot to release the pressure, and I guess it had been building up all that time. So in order to save you the benefit of my experience, maybe best to let the lid of now and then or put a pin hole in the cap. Anyway .. Night all.. Great thread BTW.. thanks for sharing this technique.. Im gonna start again in the morning !!