An important piece of disturbing information surfaced during the Rabbi Slifkin Book Ban.
It seems that some haredi gedolim permitted ideas like Rabbi Slifkin's to be taught, but only for 'outreach' purposes in kiruv (outreach) seminars and at ba'al teshuva yeshivot and seminaries, but not in regular haredi yeshivot, seminaries or communities. God forbid their own children should be perverted by such heresy.
In other words, haredim practice a double standard, the use of deceitful tactics to missionize the unchurched, to lure in the unsuspecting, just like real cults.
Learn from this ban.
Haredim will lie to you to get what they want, be it a donation or another 'saved' soul – especially if that soul is yours.