For any wound to heal quickly it needs access to air. The wound will keep itself wet while healing to protect itself, but the moisture needs to evaporate naturally or healing is delayed. You didn't mention where you have this tear in your skin, but as Alex mentioned can you somehow not apply your wafer over that specific part of your skin? Meaning if the tear is in the middle or edge of the adhesive part of your wafer........can you simply cut a hole in it directly over the tear....to let it breathe? If not, then as Axl Rose said, you need to keep it protected from the adhesive on each subsequent barrier you use. It will take longer to heal this way, but will eventually heal. What you need to find out is why your skin tore there in the first place. Has that part of your skin been weakened by topical steroids or such?
The other thing you can do if you can't let it breathe is to place a blob, pile or whatever you want to call it of ostomy powder directly on the tear. Don't smooth the powder out or brush it off, just leave it in a pile on the tear and install your new wafer. The bunch of powder will stop the wafer from adhering to your skin in that specific spot only.......but if you spread it out then adhesion will suffer all around and you could have a leak. If you have access to an ostomy nurse I'm sure he or she'd have some other proven suggestions for you. If there's none close you might be able to schedule a tele-visit with one from a larger hospital down your way. If all that doesn't help......contact Nu-Hope and talk to their ostomy nurses over the phone.