Two classic gross-out props that Kroneck likes are bowls of peeled grapes or the guts of a pumpkin with the seeds removed. These can be served up to kids as candy until they realize it's actually . . . human eyeballs and flesh!
For cobwebs that are significantly creepier than the store-bought stuff, Dahl suggests this DIY cobweb shooter, which only requires a glue gun, an air compressor and some basic plumbing supplies.
Finally, for a sure-fire kid freak out, find a place in the haunted house to strategically locate your own head in a jar.