Actually, at first attempt, lockdown worked perfectly. Locked collections and hid them when needed. After a few glitches with other apps, i've deleted original products and collection. Entered new ones, and it suddenly stopped locking. After a few hours, it suddenly started locking again, but locked collections still don't hide. No idea what's up with that.
Decided to try locksmith. I'm displaying each collection in separate table (don't ask why :) ). I tried wrapping all of tables in these 2 lines of code developer gave at support site. I tried wrapping each table. I tried wrapping content inside tables. It still shows locked products. Customers can't access them, but they can see them.
Anyone ever came across anything like it?