I used to bottom bounce spin-n-glos all the time way back when and I simply used a small safety pin snap/swivel with surgical tubing and pencil lead. Tie mainline to one end of swivel and leader to the other, the end with the snap on it. Then, open the safety pin type snap and hook it into a piece of tubing about 1/4 inch in. Snap it closed. Tubing can be from two to four inches long depending upon how much weight required etc.
Cut off lead to appropriate length, lubricate with saliva and insert in tubing. If you want to decrease the stickiness of the lead and make it a bit more bouncier then get a jar of that tool handle repair goop (can't remember name of it) and dip lead into it. Forms a soft rubber-like cover over the lead so it "bounces" off stuff easier it's claimed. Hard to objectively measure success of that methinks, but.....could be.
I never bothered with that part and didn't lose a lot of lead. With a steady and judicious pull you would often break off just the rubber and the piece of lead, which could be quickly replaced. Sometimes the lead pulled free and you needed replace only that.
But, to each his own and I'm not picking on anybody else's method, just sharing how simple mine was.
Take care.