Water won't 'wash off' machine oils. When I first cleaned my PT-2 the one and only part that was seriously gross was the inside of the drip tip. Take the o-ring off of it and actually scrub it down. I used a twisted up piece of paper towel to clean the inside and black-ness came out. On 2 protanks actually...so do that even if you aren't getting a metallic taste.
Also, anyone with a PT-1 or mini-1: If you start tasting a horrible chemical taste, do NOT assume it's your juice or something and continue using it. You could be smoking epoxy. I kept trying different things, thinking it was the juice or the coil, when it was really the glue burning. Chest pains, shortness of breath, not good at all. Look at the base of the tank on the inside under the threads, you should see the CLEAR adhesive with little air bubbles in it. If you see any YELLOW, stop using it.
One more thing, yes different devices work differently with different batteries. None of this is 100% standardized yet. Yeah there's the different standard threading, but that's about it. On one battery, a device might screw down too far and block the airflow to the devices airhole in the 510 connnection. If the draw is too tight, you might flood it. Another batteries positive pin may be too high, like on my provari mini. There's too much airflow with a protank 2 just snug on it, and no airflow if you try to tighten it down so everything is flush. Too airy and it's going to burn the wick.
This doesn't mean the PT-2 is crap, it means the lack of standardization and adjustability on batteries and devices is crap. No glue is a HUGE win though and the design is great. What needs to happen is all batteries need the exact same dimensions, and all devices need adjustable air flow. The industry is getting there though. I haven't had the best experience with the PT-2 on a provari mini, but that doesn't mean it's a bad device. Inhaling burning epoxy/adhesives IS very bad though. Just some thoughts.
You might want to also consider looking at the Kayfun lite, Kayfun mini 2.1, the Russian, and soon to come out Russian 91%. Pricey, but how much did you spend on cigarettes every month? I finally decided to bite the bullet and get a BS-free device.