FRA is a shambles when it comes to this.
I usually buy my toiletries airside at LHR when travelling to avoid the cumbersome liquids rule, but this is very difficult when my route means changing at FRA. It also seems to depend on whether I'm travelling out or back.
Travelling from LHR and changing to the same non EU destination, I have experienced:
- 0 security checks at Frankfurt (7 times)
- 1 security check (2 times)
Travelling back to LHR via FRA from the same non EU country, I have experienced
- 0 security check (once)
- 1 Security check (6 times)
- 2 security checks! (2 times)
Just a bit of consistency would be nice
The worst airport I've ever had the misfortune to travel through (taking into account plenty of experience of both LHR and IAD).