Bodoni,
What I found that worked really well (but you need to be Mcgiver here) is to use the tip of those 60cc syringes...they come with a tip cover...it is the perfect size but could be dangerous if pushed all the way in so I melt the open end over a flam or boil it and then slowly press it down until it turns into a puddled hard base large and smooth enough to not hurt me...the tip goes into the stoma, the base sits outside and I tape it down...
I have all different kinds & sizes of pacifyers too and a collection of junk acumulated over the years that works on different occasions (shrunk stoma, sunk stoma, granulation...)
Good luck