Have them push a traditionalist societal view,with high birthrates for members,and let them take in poor people at a loss for the express goal of growing and attracting richer people,and they can pull it off. Its not like obivously ridiclous theology is really a problem for getting big,mormonism and many others have little problem with that.
Traditionalism is kind of hard when your worldview goes against every major religion.
That said, using rich philanthropist Scientologist celebrity's money to rope in poor people (who will be forever kept at the low levels of the church until they can pay more) isn't a bad idea, but to some degree Scientology already does this. You can pay for more church services by signing your billion-year Sea Org contract among other ways. The CoS also uses front groups to recruit poorer people like their drug addiction programs.
I guess you could also have independent Scientologists to form a church that isn't so cult-like, so as to rival the real $cientology. After a long time (Church Wars/Crusades 2: Electric Boogaloo), this new church could "defeat" the original church through overshadowing it and creating a new impression of the "religion". Basically, have a friendlier, non-aggressive and more honest church exist in place of the OTL $cientology church.
Yes, the Free Zone aka "squirrels" in Scilon lingo, which experience constant harassment, lawsuits, etc. Hard to fight back against that.
Free Zone is also forbidden (due to lawsuits) from using certain "religious technology" and most Scientology scripture, so it's mostly pirated or knockoffs, although IIRC this is less of a problem in recent years.
Otherwise these independent Scientologists are a more typical New Agey sort of group, where they have stiff competition and an unfortunate link to the CoS.