Cee and all
Cee, from your description, it sounds like you have a stoma that drains at the skin line with uneven skin contours and the stool undermines and gets caught there. Assuming this is an ileostomy...
I will say after trying conventional methods of correcting skin contours and having no success, I will use just about anything to get containment for folks. Tincture of benzoin is pretty toxic to open skin and will retard the healing, besides hurting like crazy. On intact skin, some folks may find their skin rips off too when removing their appliance. Be cautious if you are going to use it. Some folks have no issue with it, so it's hard to argue with successes like Juno Pete. Just a note of caution.
It sounds like your nurse is on the right track. If the wafer is burning, I would suggest putting a small layer of powder (i.e., Stomahesive or Karaya) over the area, dust off the excess, then dab with a No Sting brand skin prep (Smith and Nephew No Sting, Cavilon, Relia med Sting Free) to seal the powder, then try a plug of Eakins to fill the dip, then an Eakins ring/paste or however you have been doing your pouching. A convex wafer and your belt may help "pop" the stoma out a bit more to make a spout that drains into the pouch.
Your nurse is right, you do have to keep on top of it. If the skin is moist/denuded, it will take time to heal. You may have to change your appliance every 1-2 days for a while to get a seal until the skin heals a bit.
I would not put tincture of benzoin directly on damaged skin. You need to fill the dip first: if you wanted to put the benzoin on top of the Eakins or at the edges, it should not be a problem. You also may want to try a small amount of Stomahesive Paste caulking at the junctions of where you plug the dent between skin and stoma.
There are some medical adhesives that are a bit less irritating to the skin, but messy to use. Nu Hope makes one, Smith and Nephew (Skin Bond Cement) makes one. I will only use them if nothing else works. On the powdering: I agree, it is hard to get something to stick to powder. It does help to dust off the excess, then dab a No Sting Skin Prep agent over it and allow to dry, then apply your Eakins or Paste on top. It gives you a temporary dry surface and a whole lot less stinging.
For ileostomy folks: a good goal to shoot for is 2-3 days wear time with your appliance if you are having containment and skin issues. Sometimes you have to start out with just 1 day. Due to the digestive enzymes (and individual skin makeup), the skin barriers do get broken down, faster for some than others. I will go back to troubleshooting if someone is only getting 1-2 days...but I think 3 is acceptable. 5-7 days may be pushing the limits of the protective skin barrier unless you have the perfectly constructed stoma in the perfect location. I always hope for those, but it's not always what happens. Everyone's stoma is different, and you have to judge by your own.
Juno Pete: you might find this interesting. Decades ago, ostomy nurses found that most wounds healed under occlusion of ostomy wafers/skin barriers; kind of contrary to prior wound healing theories of "airing" wounds out. There is a mega-million-dollar industry today for dressings that heal wounds by occlusion; much due to ostomy appliances.