Actually, folks, this substitution of English nouns for German ones, is an active Linguistic process going on in your brains, due to "Local Language Submersion" - in other words, being surrounded by German/Swiss German every day is causing it to happen to you subconsciously.
And resisting it is very difficult.......... goes against nature, you know!!
As a German, I am usually more irritated by "German" terms used by my English speaking colleagues at work: They are usually Swiss German to say the least, quite often some Bernese slang words I would even not understand if they were pronounced correctly... And the rethorical "oder?" question at the end of each sentence already annoys me in German.
So my recommendation: Try to keep in mind where the term is used, is it Swiss or German?
You will get at least some funny looks if you ask for a "Stange" in Germany. The word means "stick" and is often used in Germany to describe an errect... well you guessed it. "Kann ich eine Stange haben?" will not get you a beer, oder?
I've been here for so long that I throw (Swiss) German words into English sentences and don't even notice anymore....until of course my English-speaking counterpart raises an eyebrow and asks me what that last word was...such as "handy" for cell or "beziehungsweise" (??) or "grundsätzlich" (in principal).
My daughter only speaks Swiss-German to me at the moment. I love how she says, "so, so" and "Macht nüüt" (it doesn't matter / don't worry about it).
My american ex girlfriend had cooked for me in Scotland, and I said it was "not too bad". she was a wee bit un-cheerful for a couple of hours afterwards.
Don't use it so much any more but I used to say 'Scheiss die Wand an' quite often, also Schnecke for cute girls. My best friend in high school (U.S.) was Bavarian and picked up some bad habits from him. Also referred to anyone remotely ridiculous as a Popper.
Speaking of which, why doesn't anyone use "cell" as the name for a mobile phone?
As for me, I often find myself using "scheisse" and have caught myself on a few occasions saying "Tschüss" oder "Tschau" before hanging up the phone. I live in Canada! lol