I used to experience that a lot, and that was after wearing the same type of appliance for a year. Then I sent away from samples from all of the ostomy companies. I now use Sensura by Coloplast and I love it. Instead of the Eakin seals, I also use the Coloplast paste strips.
I used to itch so bad it nearly drove me mad. Now, I hardly feel like I am wearing anything.
Never heard of the Maalox trick. With the Coloplast Assura and Sensura, they suggested that you don't put any kind of skin prep on before applying unless you have red, broken out areas. Then they told me to apply skin prep, powder and repeat. I have not had to resort to that since I switched manufacturers. It appears (in my case) that I became sensitive to my original brand after a year!
Hope this helps.