Backdrop idea #1
What each device could do:
Home Defender 2000: A large rocket for use in the home. Funny due to the fact that explosive firearms are readily available for everyday use in the American home in this universe.
Flying Tank: Self explanatory. Small, comedically ineffective wings.
Alert-a-thon: Supposedly alerts the wearer of people breaching the american border. Funny due to the fact it is a colander with a siren stuck to the top.
Commie-b-gone spray: Sprays the wearer with the 'scent of democracy' to supposedly scare away communists.
Pie mine: Deliver to your next door neighbor should you suspect them being aliens or communists as a friendly 'gift'
Brainwave reflector: Supposedly block radio waves from aliens that control your mind.
Portable shelter in a box: A large, cement box to jump into lest a bomb explodes. Completely impractical as a portable device. Large and heavy.
Invader repeller 2000: 'Repel' the invaders of freedom and democracy with this top-of-the-notch invention! Funny due to the simplistic and barbaric design.