I don't give a flip about "Arab tribal customs", and neither should any other genuine conservative. So long as people aren't practicing terrorism or otherwise imposing themselves on others, the idea that we have a mandate to rip people from their cultures in the service of a Greater Good is a perfect example of the Gramscian way so-called conservatives have let themselves be morphed into monster-state utopians.
The reservation of footwashing for men only is archaic only if you strip the rite from its ecclesial context as a sign of Christ's institution of a priesthood to mediate his sacraments for the world's salvation, and reduce it to a social service that fits comfortably in the categories of a secularist world that always has and always will look for ways to tame the Church.
Well put, Romulus.