I think it depends on the treatment
Coppola is DEF wash and wear...that junk wears off really quickly. The stronger treatment my stylist used in my hair called Donna Bella Perla is still hanging strong...the bkt's I've done on top of my Donna Bella w/coppolla wear off...but the Donna Bella Perla Hair is still hanging in there and I did it back in early June. My roots, even after several applications of the Coppolla are still a much tigher curl than the rest of my DBP BKT...weird...
Also, you use QOD max/gold, right? How strong are the fumes?