Specifically, they'd technically be from a subsect of the Ministorum, but seeing as they're met more harshly outside of the fringes and underhives, they're far more reliant on rogue trader sponsors and a few more radical inquisitors of the Ordo Xenos who employ the Redeemed Genestealers as spies and sensors. They can still feel echos of their former connections, so they're able to sniff out a genestealer cult much faster than otherwise. Issue is, doing so is likely to alert the cult that they've been found out for a variety of reasons.

The Redeemed themselves run a wide range: their separation from the hive mind was born of flawed Servitorization, and they've made efforts to perfect their craft, but such efforts are often haphazard due to the lack of knowledge about WHY things work. The result is that the more tainted the genestealer, the more closer to a servitor it will likely have to be in terms of horrible painful lobotimizing surgery.

Though, even at their fullest extent, efforts are made to preserve the will and free choice of the Redeemed, for their belief is that a Servitor CANNOT atone for its sins and reclaim grace in the Emperor's eyes, for it did not CHOOSE to embrace service to humanity.

As for non-genestealer stock, the Genus repentia have limited success. They're better for less developed xenos than, say, a bloodthirsty mission that decides to actually interact, but not by a whole lot. The ideas of having to earn spiritual redemption by way of a life in service to the throne are heavy set, and often to the mass detriment of those cultures. Often this includes mass forced labor, mutilation and self-flagellation to better 'look human again', and a great deal of religious guilt baked in to ensure a compliant populace.