OK, and a similar question: if one used the toilet at the workplace and can say asher yatzar immediatelly after in the corridor where he can be bothered and interrupted or wait one more minute to be able to say it in the privacy of his office, with much more Kavana and nobody can interrupt?

Listen, you're asking the wrong question. The right question is: when do I have the mitzvah in front of me? Right now, when you just came out of the bathroom. That's when Asher Yatzar has to be said - immediately. Don't delay it. Now, I understand what you're thinking - you want kavanah, you want to focus, you don't want interruptions. That's beautiful. But here's what you need to understand: the yetzer hara loves when you delay a mitzvah. The moment you say "I'll do it later in my office where it's quiet," you're giving him an opening. And you know what happens? You get to your office, the phone rings, someone walks in, you start checking emails, and suddenly you forgot - did I say Asher Yatzar or didn't I? The solution is simple: stop right there, step to the side of the corridor if you need to, and say it with kavanah right then and there. Look, we have these Asher Yatzar posters specifically so you can read the words and have kavanah. If you don't have one with you, then yes, say it by heart, but say it like a human being, not like a machine. Take those 20, 30 seconds and thank HaKadosh Baruch Hu that everything worked, that all your holes are where they're supposed to be, that everything came out properly. You think people are going to interrupt you? Let them see a Jew thanking Hashem. You're not doing anything wrong - you're fulfilling a mitzvah. And if someone does interrupt, you'll finish afterwards. But don't push it off. The mitzvah you have right now is the most important mitzvah in the world at that moment.