To me the best idea would be the following:

Take a corpsified bucky or blucky, lightly wrap with the cheapo "spider-web", then attach the bucky/blucky to the upper corner of a room. From that point just cover the corner/corpse with a web shooter, trying to get the surrounding 3'-4' area. It will look like a spider has just stored the victim in the corner and fed on him/her.

Web shooters can make THE BEST looking webs. If you can find the perfect balance of webs your web victim will look very realistic.