Chris,
I think your on to my thinking! However, at SOHO distances the limiting magnitude is much higher, maybe its possible with a videocam. The most impressive daylight observation I've seen (made 2.5 hours before sunset) is this image of M57:
http://mallincam.tripod.com/sitebuil...dayfinal3w.jpg
When you stretch the image you can see mag 12-13 stars quite easily. 8 Degrees from the sun WILL be a different story, however, and I think you would loose several magnitudes so I do think it is good enough against SOHO!
Terry