Just my take, but the Ooze cult are kinda the fringe creepy weirdos that nobody quite trusts or understands so it fits the ooze more thematically to not have sendings so they are always on the edge of your typical PC's awareness due to them not making sendings and knowing what they are doing via hearing their sendings.
It sucks not having sendings for a number of reasons (would be nice to have some form of communication at least to other ooze PCs) but it isn't impossible.
It sucks not having sendings for a number of reasons (would be nice to have some form of communication at least to other ooze PCs) but it isn't impossible.