I'm wondering if blood can be made less appealing to ticks by introducing something to it? Take the internal systemic control approach rather than external. In Horticulture we can take a similar systemic approach in making plants less appealing to insects where the insects evolve - "learn" - to not to eat some plants just as they eat some plant parts and avoid other parts of the same plant for different reasons. Some plants have evolved to defend themselves against insect, disease, and animal predation taking an analogous approach.
I also wonder if some moose aren't already less prone to tick predation in the same region because they are already evolving to defend against the ticks?