Nothing scary. Maybe creepiest was they were calling daily, all the time, and no amount of pleading with them would get it to stop. Constant calls. My husband got really pissed and went to his friend who was a scientologist, and said- I'll never bring you business again if these calls don't stop.
Literally never had another call again- ever. That was creepy, over a year trying to get them to leave us alone, all it took was one sentence to that one guy.
But to backup, how we got involved- my husband had a friend who was very into the church. We finally go to check it out- morbid curiosity. We had a newborn at the time and brought her. Got a huge tour, then we sat in a big theater room alone and watched a Scientology movie. Tom Cruise was in it. I breastfed my baby at this time and felt like- welp, they are definitely videotaping me right now! Thinking they'll use my boobs as blackmail! My tits are going to be in a Scientology archive room forever! Cool!

After the movie I asked about aliens and Xenu. They denied it all. Feom this point forward, they specifically concentrated on my husband and NOT me. I wondered if my breastfeeding theater antics threw them off, or if I just came across as 'non-brainwashable'?
My husband did many months of 'audit' classes before I finally was like, ok this is creepy and knock it off, it's costing too much money.
We still have a large stack of Scientology propaganda. Fun stuff.