According to MAPS 2020, those in LSM 6-10 rank 7.1 on a 10 point scale in terms of brand loyalty with their toiletry shop, vs 6.5 for those in LSM 1-5. This suggests that in the lower LSMs other factors (presumably price) are more important than buying a trusted brand.
Analyse the MAPS data yourself with a free Data Portal trial (Some MAPS data will available on Thursday) https://dataportal.eighty20.co.za/signup/