It's like asking the question how far back do you go? That is...if cards can retain those memories..Why not ask the question, what about the tree that was cut down to make those cards. Surely it's spirit weeps.

Many of us 'bless' our cards and have said thanks to the trees already.

Hi!

As far as cleansing tarot cards, there are a few methods you can do.

use the four elements: salt for earth, water, incence for air, and a candle for fire. or just use one element-whichever one you feel a stronger connection to.

I, myself, have used fire to cleanse my cards.  just pass the deck over the flame a few times (without catching the cards on fire!LOL).

also leaving them where they can be "bathed" in full moonlight is another method.

Basically, whatever speaks of cleansing to you.  then you can program the cards with your energy and positive thoughts to replace that of your friend's.
simply sit and meditate with cards in hands, send your energy and positive feelings, etc into the cards.

Hope this was helpful.  

Blessings and Peace,

Reikiwitch929

First of all, does the deck feel comfortable to you? Sometimes, no matter what you do, the deck will never be yours. Right now it is infused with your friends energy. All the advice above is good, but the advice about handling it is perhaps the best. Putting your own energy, your signature, into the cards is the best way to claim a deck.

Good luck.

How do you use crystals for this purpose?