P30 Chem Life In Prito

Based on my experience and the literature I know I can store mixed cibachrome chemicals a couple months. How about out of a printo? For 2-3 custom prints I just use the CPA and for 100+ prints its a no brainer. But now I have the need to do 20-30 prints at a time and do not want to do them by hand nor do I want to waste 3L of P30. I know the Printo will cross contaminate the chems but if I drain them and store them after use how long can I expect them to last?