Photoshop :: Creating PNG With Photographic (transparent) Reflection?

I'm trying to create a PNG file that maintains its reflection which was captured in-camera. The end result would be that the PNG could be used over any colored background (easy for the object) and the reflection takes on the color of the background (not easy to achieve if you can't multiply the reflection over a colored background).
 
The image was shot on a white background but needs to be able to fall on any color. It would be easy to use the path around the object to isolate the background to a new layer and simply set the layer to Multiply. I realize that, but these PNG files could end up being used by anyone, and they may not have Photoshop, but rather - Powerpoint.
 
I've developed a process that does this to a degre, but I end up with a white halo around the feathered edges of the reflection (not shown in the example above - see below).
 
In the shot above, I've split the (very subtle) reflection in a layer set to Multiply, seen to the upper left along the edge. To the lower right is the same reflection with a white hazy halo bleeding into the feathered edge, and this was generated using the process below. Remember, everything is shot on a white background so the reflection has white feathered into it. I'm like this close to desirable results, but the haze has me stumped.
 
Here's how I got the right side to be transparent without using Multiply, and saving as PNG. Anyone who opens the file should be able to place it over any color background, supplied to them in PNG format.
 
1. Using high res JPG image, convert "Background" to Layer 0.
 
2. Activate Path 1 as selection, invert selection and copy all area around product. Paste that copy to new layer.
 
3. Using same selection, delete all area around product in Layer 0. Now the product is on a separate layer from the shadow and reflection.
 
4. Duplicate reflection layer and invert. Turn off all other layers. Go to Channels pane, select Blue channel - Command-click channel - Copy.
 
5. Return to Layers pane and add layer mask to reflection layer. Delete duplicate layer from step 4.
 
6. Go to Mask pane (CS5) or Properties (CS6) and click on Mask Edge. Slide the Shift Edge parameter to +100.
 
7. Run Levels on reflection layer - set the Input mid to .96 and set highlight Output Level to 250.
 
8. Select background image area using mask - subtract subject from selection using path and run Exposure on reflection layer from menu command: Image/Adjust/Exposure: -0.24, -0.15, 0.70. (Using an adjustment layer for Exposure will not work. It saves to PNG with a different outcome when reopened)
 
9. Set reflection layer opacity to 60%.