I only have PN in my feet so put around 1/4 of a cup of epsoms in a basin of luke warm water and steep my feet (sometimes for up to an hour but at least 30mins). This gives immediate pain relief which lasts for some time. Good luck.

OK, but add a bit of warm water every 15 mins or so.
Otherwise the water gets really 'cold' (room temp)

I let the water go cold as it helps with the intense burning, am I damaging my feet more as the circulation will decrease in cold water?

To the OP:

I have SFN. I am not taking Gabapentin.

I am not an expert, but I cannot imagine that you would not want to get as much exercise — of any kind, no matter how modest — as possible. Even if this means that, on some days, you have to force yourself to move around.

It was foot pain that put me on the road to my diagnosis of SFN. After nine months of following the supplement regimen found on this site (mostly mrsD's recommendations), my foot pain is vastly reduced and, in fact, almost gone. I have experienced great improvement on the supplements, with only small setbacks. You will want to search through the site, but certainly B12 and magnesium are key for us.

Good luck.

P.S. I just finished my daily 50 min. walk up and down a steep hill. Walking and bicycling are where I am getting my cardio workout now. It is kind of pathetic compared to what I was doing in the gym only a year ago, but it's better than nothing.

Do what works for you. I just would avoid hot water. And too much salts. Too much would pull water out of the feet... and be counter productive.

I think the TIME in the soak is the most important thing.