I'm a cheapskate luddite who really can't "taste the difference".
For brining the (only a couple of) small hams I've done, damp curing bacon in poly bags, and brining before charcoal grilling and hot smoking - I've used perfectly ordinary UK table salt.
And its been fine.
No bad "metallic" or "bitter" off-tastes that I can detect as such.
Remember that the UK anti-caking agents are present at a level of mere teaspoonfuls per tonne of salt, and the iodine is barely higher.
I've got no objection whatsoever to iodine at that level (thyroid), but I'd be quite happy to lose the anti-cake stuff.
I note that Erlandson advocates the use of "pure vacuum-dried salt, which is very cheap" and which "can be purchased from most agricultural merchants". He also recommends looking in the Yellow Pages under "Salt Merchants", which doh !
I've only just done...