I was told by my nurse 12 years ago not to use any soap because it would cause the appliance to not stick well. I have never used soap and have no problem. I also have a rather large (fist size) hernia. I have never used adhesive remover. I have had the odd failure due to sweating while working on a hot day. I find that I need to use a belt at least the first day after changing out my appliance. This assures a very good bond. I use a Hollister two-part system for my eurostoma.
Here is a wee hint..... I always shower and dry off before I loosen the surrounding outer tape on the stoma and then quickly rip off the inner tape. It is probably less painful to do it that way and for sure leaves very little residue glue behind. I then just rub the area down with a baby face cloth. Heat the appliance with a hairdryer, dry myself with a folded paper towel and the hairdryer, being sure I am totally dry. Then apply the warmed appliance. This works very well. I might have one or two failures per year.