A little bit of soybean oil can add a nice silky quality to the lather. If you keep it at less than 15% and the balance are stable oils, it shouldn't be too DOS-prone. I don't use it any longer in my formulations but it has a place. I've given up on rice bran oil too (for soap) as I prefer olive oil and it's one less thing to measure out and store. I like rice bran for lotion, however.