House Elves and Clothes

[Rachael]

No: HPFGUIDX 65172

House Elves can only be freed by getting clothes from their master
(s), so what about laundry?  I was under the impression that Elves 
did the laundry at Hogwarts and that Dobby, since he was able to iron 
his hands without anyone noticing anything funny, did the Malfoys' 
laundry, ironing, etc.  If a wizard hands a stack of dirty clothes to 
an Elf, does he have to precede that action with a statement of, "I'm 
not freeing you, I'm giving you work."?  Obviously to free the elf, 
nothing has to be said along with the clothes or Dobby would not be 
free.  Any suggestions other than I need to stop obsessing over Harry 
Potter so much that I wonder about trivial things like this?

Rachael
Bratty