Hi BotF *waves*
It might just be that you haven't found the right food yet. I make home-made liver cake for our's (recipe came from puppy school) and whilst Rascal likes other food - she'll do absolutely anything for liver cake - it does smell quite a bit which might be why!! Squidges nicely into a kong too and doesn't just fall out. Here's the recipe if you want to give it a try:
1lb of liver (I've used pigs, lamb, chicken - whatever's available and cheapest)
2 eggs
2 cloves of garlic, peeled
a cup of milk
1llb plain flour
Whizz the liver, milk, garlic and eggs in a blender, then fold in the flour - add a bit of water if needed to make a cake like consistency. Line a large baking tray with baking paper then pour in the mixture. Bake at 180 degrees for about 15-20 minutes until it's firm but not dry. You can then cut it up into approx 1cm cubes and separate into individual bags - it freezes well so we just keep one bag out (it only lasts 2 - 3 days in the fridge). Works out pretty cheap too compared to shop bought treats!