stainless has been a "kinder" feel to me than gold. Gold had more hot
spots. I think the stainless electrodes coat themselves with a passive
oxide immediately on first use, and this tends to smooth them a bit.

time: beyond an hour I get skin issues, and it matters less the level
of current than the uninterrupted duration of usage. Beck only tested
the 4 herz design 2 hours a day. I think DC is 3 times as corrosive,
at least. Skin has to have time to recover.

bG