removing rust type stains

Does anyone have any hints on how to remove rust stains from clothing? DS is having a liquid iron supplement and kindly rubbed his face all over one of my favourite white tops and some of his clothes have some marks from it as well. Soaking in the machine with napisan (about 2 hours) hasn't removed it. Tried doing this a couple of times and not much luck there. It doesn't seem to have faded in the week that I left the clothes on the line in the sun the other week. I've also tried supercharging my wash with the SA8 gel stain remover (Amway product which usually gets things out) and napisan and the Amway stain remover bleach stuff (non-chlorine based)

Currently I'm trying a really long soak in the laundry tub with napisan (i.e. I put them in there last night and I'm intending to wash them tomorrow) but if this doesn't work does anyone have any other ideas?

try CLR