I don't know about a slot...Melt the end of some line and pressed it into a ball. Make the other end pointy to poke through your patches. Used mine hundreds of times, never broke it.
I got the .080 weedeater line 3 bucks at wally world and works great, I heated the end up and pushed it into the back of a pellet, made a perfect shape and never lost a patch, got the idea off the forum somewhere.
Brass rod is not so bad if used just to pull patches through, breach-to-muzzle. I don't use them, but you can get away with it if you're careful. You never want to scrub up-and-down the bore (especially with brushes), and you really don't ever want to feed the rod through the muzzle, lest you damage the crown.Also, lots of airguns don't have enough clearance around the breech to thread a patch. Breakbarrels sure, but sidelevers or bolt-breech guns are trickier.Weedwhacker line works great, because you can first thread your patch, and then feed up from the breach even with very restricted breaches, like say a Crosman 2100 or a 2250.The author of this post states that he wants to clean his 2100, and it would be a pretty dicey go with a brass rod kit. Weedwhacker line or CrownSaver would be the way to go in his case.