Hi Nathalie,
Good question. I imagine that one of the ways you could do this is to infuse oats with oil. The way I would be inclined to do this is by blending the oats and oil together over the course of 8-12 hours, at 1-2 minutes at a time whenever you think of it. Then strain through muslin (fine). Don’t squeeze too tightly just let it drip through.
This would then be the base oil in the salve. Another idea could be that you could grind the oats into a fine powder and just add this to a salve mix. The only thing here is that it would make a grainy texture.
Don’t hesitate to ask if you have more questions about this.
Warmly,
Benna