That’s a great question! The only cleansing I tend to do before a tea leaf reading is mental- focusing the mind and drawing in energies 
When I studied the Japanese tea ceremony, we were taught that pouring the hot water into the vessel is a kind of ritual purification- and that always stuck with me 
As for cups, come people have beautiful tasseography cups with art or designs inside the cup that help with readings (the lovely @Berta shared her amazing tasseography cup). Alas- I haven’t got my hands on one yet! For now my readings are guided by nothing but pure imagination 
And your tarot pouch is lovely! 
That’s such a great idea for transporting the cards.