Guide for pixelating particle effects using render textures

Greetings all,

I'm fairly new to Unity, and trying to figure out how to pixelate particle effect prefabs obtained from the asset store. I'm looking for any guide or advice on the best and most flexible way to implement this. I'm working in 2D of course.

So far I have this:

1) Added 'Particle' layer, removed Particle layer from main camera so as to not be visible

2) Added 2nd camera that only captures the Particle layer and renders to a render texture set to 512x512

3) I put a cube and added that to the scene with the render texture on it. Scaled it to achieve the pixelated look I want.

I got this to work with just plopping the prefab in the scene and setting it to loop, but when I instantiate the prefabs via code it doesn't seem to work. Should I be doing this a different way other than layers? In the code I'm instantiating and setting it to the 'Particle' layer, and verifying that in the hierarchy in play mode, but it doesn't seem to work.

But I'm going to have lots of characters doing this with lots of particle effects. Is this the best strategy to use? Render all the particle effects to a single rendertexture and then blow it back up, taking care to make sure it's aligned back to where it should be?

I feel like I'm either making this more complicated than it needs to be or there is a better way that I'm not seeing.

Any advice or suggestions are welcome! I found this guide which is helpful, but doesn't actually explain how to do the render texture method it mentions:

https://imgur.com/gallery/z4Boura

Thank you!