Per-object glow without using camera bloom

I'm trying to make interactive objects glow but I don't want any light objects to cause bloom, which they do even if I put the intensity and threshold up very high on just the interactable objects. I've tried a second camera with layer culling and depth off, but the objects appear when they're supposed to be obscured by geometry and the bloom is still affected by the other cameras lights. I can't figure out a really good way of just having objects glow and not lights or anything else bright. Is this possible at all? I'd even settle for a shader that was faked it, like an outline.

 

Have you seen this video?

 

Thanks, that looks good but the rendertexture method is a bit strange when resizing the game window, it seems to be locked the to initial size of the window. I could try resize the rendertexture size if the window size changes, is this the only way of really doing this, even with post-processing v2?