Making flea trap refills

 How can I make my own flea trap refills?  I have some index cards
that will fit in the traps.  All I need is something that will stay
sticky enough to trap and kill the fleas.  Would petroleum jelly
(Vaseline (tm)) work?  Thank you in advance for all replies.
--
My previous cat Rocket thought that every time I ate something he
should get some canned cat food.  Marmaduke, the cat I have now,
thinks that he should get canned food and be allowed to get on the
table and eat what he wants off my plate.

 
Why do you need to refill the fleatraps? I just open the wire spring
with tweezers and the dead flea falls right out into the wastebasket.
Add more bait as required (bloody peanut butter is good), and then
carefully reset the spring.

Don