Yes, from what I've read it has to be ONLY MO. A baby oil with added vitamin E, aloe, lanolin, or something else like that may not work as well.

Mine isn't fragrance free, so I dont know if scents are an issue at all, but I've not noticed any problem.

There are several articles here that talk about MO. One was just published in April of this year and is based off of new studies. I think it was called "Has mineral oil gotten a bad rap?" or something like that. It was the one that convinced me to try it!
2c/3a/3b, Fine/med, Dense, high porous, & normal elas.

Lo-poo - Renpure Keratin, SMR, Giovanni SaS
clarifying - mix Johnson's H2T with low poo
Co-wash - Suave Nats. clar. or coco.
RO - GVPCB, Ion Eff. Care, TN.
LI - SMR, Cure Care, or RO
Seal - MO or Jojoba
DT - + honey, ACV, & EVOO to SM masque & GVPCB
PT - Gelatin!, CNPF
Styling - FSG, AIF, BRHG, LALS/PS, GF curl spray gel, SM Souffle/Smoothie, LOOB
Oils - MO!, EVOO, jojoba, GSO, SM Elixer, EVCO, VO5 Hairdressing