I use the Coloplast Assura Extended Wear wafer with built-in skin barrier (item #2833). It's a two piece system, so the pouch snaps and locks on and has a velcro closure (item #13986). I've been getting 7 days wear time out of the wafer and put on a fresh pouch every 3-4 days.
I also use stomahesive paste and nothing else on my skin under the wafer, since it has a built-in skin barrier. To remove the wafer, I use an adhesive remover wipe and clean the skin in the shower with Dove soap for sensitive skin, which is fragrance free.
So far, this system has kept me leak free for over 2 years. I've even spent the day swimming at a waterpark and still get 7 days wear time! So, it's definitely worth giving it a try.