If I want to taste bacon, I'm going to eat bacon. I care not for any "bacon-flavored" goods or any "bacon substitutes". It should only taste like bacon if, in fact, I am eating bacon. It should only be a bacon substitute if I am substituting one strip for another, fattier strip.
I wonder if bacon grease could be used as a substitute for some of the oil in mayonnaise. The fact that it's solid at room temperature might prove problematic.