I have adhesive allergies, that I learned the hard way with my flanges that have the paper tape around the outside. I had irritated my skin so much, it started weeping clear fluid. Ever try putting tape on wet skin ..... doesn't stick very well. It turned out to be a yeast infection (that my girlfriend wasn't so happy to hear about after her having issues with getting them in the months past, for what was an unknown reason). I got the issue fixed and stopped using flanges with a tape barrier. But, then I started running into greater leakage issues. Maybe it's just the shape of my stomach, but without the tape barrier, it would be less than a day before the flange would lift at the top to the point I would see part of my stoma.
So....the best solution I've found lately is that I use Convatec moldable flanges with the tape barrier. The adhesive on the tape is the same as the flange, so my skin doesn't break out. I don't stop there, as I find the tape barrier slides on my skin and lifts after a few days.
My second layer of protection is the 6" Duoderm sheets. I cut them into 3 strips and then notch them out in the center about 1/3 of the way. I then frame the two sides and then the top, around the plastic part of the flange the bag clips onto.
I get 4 - 6 days wear out of this, depending on how often I shower. The Duoderm around the outside acts as a second barrier. If I lose the first seal closest to the stoma, I then have that backup to give me time to get a new appliance put on.
The Duoderm is expensive, but my employment benefits cover 100% of costs, so it doesn't matter to me.
One side note, by changing less, my skin is happier. If I have a leakage in the first few days, removing the flange from my skin is more difficult and can sometimes rip the skin.