I use Mineral oil mixed with clove oil. I think my mixture was 32 oz of mineral oil to 1 oz of clove oil. The clove oil mixes well with the mineral oil and seems to help it stick better. It smells great also and is completely food safe, IIRC clove oil actually has certain healthful properties, though that was not why I added it. I had heard that it was used for Japanese swords in days gone by and I thought it might be interesting to try added to my mineral oil.
I have a small capped squeeze bottle in a ziploc baggie with a soaked wipe cloth in another baggie. Both of these go in a slightly larger baggie plus a small piece of scotchbright for sap removal before resheathing, and that is my travel carbon steel blade maintenance kit.