I didn't publish anything till this month, and the time has come!
This is a shader-based asset I made for my friend's VRC world "Nier Automata Flowers" more then a year ago. And now I've been asked by my patron Sheyne to share this asset with people now, so here it is!
Basically, what it does, it glows up anything you touch with any objects, or even your avatar's fingers and body.

Download the file at the bottom of this article.
First, you need to know that it uses several cameras and render textures. And it does not support curved objects properly. I mean that the object can be curved, but not the surface on it you want to glow.
NOTE: You must have Post Processing 2 asset in your project to make all the stuff work!
One camera should be on your mesh which you want to glow, and should point outside the surface, like this:

This camera is orthographic and basically it just writes depth to the Depth render texture.
Note that it's culling mask must be set to layers which should interact with out mesh and cause glowing. (Players, Pickups, etc.)
The other cameras are something you might not change, but I'll talk about them too. They are placed inside the Buffer object. One camera stores and animates glow fade effect using Buffer Render Texture. And the second one applies some blur to it with the Post Processing Stack 2 and writes the result to the Glow Render Texture, which is finally used by our mesh's material.
That's how it works actually. Ready to use glow texture on the left. Then goes the buffer object which shows us the buffer texture. And then at the right, our mesh with the glow applied:

NOTE: You may delete object that visualizes glow at the left, but not the buffer object! Buffer object must be active and not even scaled to zero! Just place it somewhere outside the play area visible to player.
To control your glow fade speed, just change a parameter called "Dissolve Speed" in the Buffer Material.

I'd also recommend to use my special Standard Glow shader for you mesh to have a possibility to mask your glowing texture:

Note that using this asset may cause some performance issues. So, that's some rules how to optimize it: