I have never seen or heard of the setup you describe with a baffle between the speakers but I have experimented with several electronic gizmos that are designed to address this issue.
My favorite is a discontinued product called a BSG QOL processor. This unit goes between the preamp and the amp and it adds a significant illusion of depth to the soundstage. One of the nicest things about it is that you don't have to have your head in a vice to get the effect. I use it all the time - it makes virtually everything sound better. I bought a second one in case it fails. It got good reviews in Stereophile and TAS. They come up ocassionally on the used market and sell for a few hundred dollars (it retailed for $4K new).
I also have a Carver C-9. It works well to add depth and detail to the soundstage but you have to set it up carefully and you have to have your head locked into position to get the effect.
I also have a Black Ice FOZ SSX sound stage enhancer hooked up to my desktop system and it works very well. I tried it on my main rig and I didn't like it nearly as well as the BSG. Black Ice also makes a cross-talk reduction device that I haven't heard.
The newest kid on the block is the BAACH Spatial Audio system. I haven't heard this yet but I'm looking forward to checking it out. From the reviews it sounds similar to the Carver unit in that you have to calibrate your head position exactly in the setup. That would be a deal killer for me but I would like to hear it anyway.