says Divemaster Candidate
Actually it's more concerning as his profile states Divemaster/DSD leader!
At the OP:
At your level, you should know this and have a good understanding. However in the spirit of helpfulness...
You Know (or should) that the amount of lead you need is there to offset the buoyancy of you, your equipment and your exposure suit.
So this means at the end of a dive, with minimum gas in your tank you should be neutral with no or little air in yoru BCD.
If you are wearing a thick exposure suit, then this will compress at depth losing it's buoyancy. Thus in the event of a loss of buoyancy (BCD failure, or perhaps OOA requiring you to become slightly positive, you need some method of removing enough weight to allow you to initiate a safe positive ascent.
If however you are divign in the tropics with just a rash vest and board shorts, you have no exposure suit compression and thus it's likely you wouldn't need to ditch weights - although being able to ditch a little has some benefit
The decision as to how you achieve this is entirely up to you.
That said, given that you're a DSD leader and a DM and may be demonstrating skills, you should ensure you can use similar equipment to your students for weight ditch and removal.
May I also respectfully suggest you have another look at teh Encyclopedia of Recreational diving, which will cover this in detail