Suspendots or sticky lead

I got some off ebay for Tennis rackets or golf clubs, don't remember which now but I guess you can go to a proper golf/tennis shop, they use it to balance their golf sticks etc. Cost about a fiver for around 20g or so of sticky strips in different weights, not that it mattered what their pre-set weights were, I just cut it to suit.

You could try carp tungstun putty - goes rock hard in water although it will have to go around the hook or split link as it needs something to grip ...

I use the golf club swing weight stuff.

also, for added weight try...

rubber cored sinkers or split shot (squeeze both onto the hook shank)

solder, in various gauges or lead cored line. I use both.

Small lumps of car body filler. add more then sand as required. It dries quickly.

Epoxy over thread. Whip hook shanks, add epoxy. This adds colour flash, I use red. epoxy adds weight. I usually do this on the
front hook only. no rules though as long as balance is maintained. (if that is your desire of course).