Got through this, but my knowledge of the theme (despite the obvious hint in the title) is so limited that I had to do a complete trawl of a long list.
Lucky i speak German, 33d will be unknown to most people and the word has never featured in English, unlike other germanic words, such as wunderbar... or Fest
Gerba, the clue itself was so easy, I don't think any German was really necessary!
In Germany sail south-east round Glen (6)
And the crossing letters helped even more - ?E?ELN
I was so sure 40 had to be Peter someone - was held up for a long time but got there with considerable help from Google and did my blog Friday morning. I too thought 33 was a bit steep but that's Doc for you.