Some kinds of meditation stimulate it. I've tried those.

Where did you hope to get?

Not GP, but there is

https://www.psychologytoday.com/us/blog/the-athletes-way/201...

Not sure if this is a good idea though.

There is this technique: https://therapyinanutshell.com/vagus-nerve-exercise/ that seems to stimulate the vagus nerve.

Place your hands on the back of your head, with the fingers interlocked, and the thumbs pointing down gently pressing/rubbing on your neck.

Slowly move your eyes to any fixed direction (say, to the right) and keep your eyes open, staring to the right.

This will initiate a yawn or deep sigh in most people, stimulating vagus nerve.

What kind of sorcery, i tried this and yawned within second.

Interesting, another poster called it sorcery but I tried it three times and nothing happened.