[HPforGrownups] Why would RAB put poison back into the bucket?

[Sherry Gomes]

No: HPFGUIDX 137723

Why put poison back into the bucket?  What does RAB have to gain by 
replacing the poison?  Assuming that LV set up the Horcrux and then 
RAB comes along and takes the locket, I am left wondering.why leave 
it with the same protections as before?  Whoever took the locket left 
a note, a note written to LV, so why bother to replace the locket?

Greenfirespike



Sherry now:

I've wondered if perhaps the potion replenishes itself.  You know, someone
drinks it, and eventually it reappears in the basin.  Maybe, that's a way
out idea, but there has to be an explanation why it is there, if RAB had to
drink it previously.

sherry